Semantics aside, every season baseball analysts use empiricism to meaningfully distinguish between "contenders" and "pretenders."
Every single World Series participant in recent years has featured both star power (at least one 5+ WAR player) mixed with excellent depth (at least three "4 WAR" players, and five "3 WAR" players):
2012 Giants (one 5+ WAR, five 3+ WAR) vs. Tigers (two 5+, seven 3+)
2011 Cardinals (three 5+, six 3+) vs. Rangers (four 5+, ten 3+)
2010 Giants (two 5+ WAR, seven 3+) vs. Rangers (one 5+, six 3+)
2009 Yankees (three 5+, nine 3+) vs. Phillies (two 5+, seven 3+)
2008 Phillies (three 5+, six 3+) vs. Rays (two 5+, five 3+)
Last year we didn't meet either criteria: not for star power, and not for depth. The only player who came close to 5 WAR was Reddick, and he only did so on an absurdly inflated UZR. Cespedes (3.1) and Parker (3.7) were the only other players to post a WAR above 3. No prominent system projects any A's player to post 5 WAR next year, and fringe talents like Coco Crisp and Brandon Moss will have to produce very well in order for the A's to get 5 players with 3 WAR.
Here are the AL teams who return players with 5+ WAR:
Tigers (Cabrera 7.1, Verlander 6.8, Jackson 5.5, Hunter 5.3)
Rays (Zobrist 5.9, Price 5.1)
Rangers (Beltre 6.5, Darvish 5.1)
Angels (Trout 10)
Yankees (Cano 7.8)
Mariners (Hernandez 6.1)
Royals (Gordon 5.9)
Twins (Mauar 5.0)
Now lets take a look at AL teams returning players with a 3.0 WAR:
Tigers: 7 (Cabrera, Verlander, Jackson, Hunter, Fielder, Scherzer, Sanchez, Fister)
Rangers: 7 (Beltre, Darvish, Harrison, Andrus, Kinsler, Murphy, Pierzynski)
Angels: 5 (Trout, Puljos, Hamilton, Aybar, Weaver)
Jays: 4 (Bautista, Reyes, Johnson, Encarnation)
Yankees: 4 (Cano, Jeter, Sabathia, Kuroda)
Royals: 4 (Gordon, Moustakas, Shields, Butler)
Rays: 3 (Zobrist, Price, Jennings)
Indians: 3 (Swisher, Santana, Kipnis)
Red Sox: 3 (Pedrioa, Ortiz, Lester)
White Sox: 3 (Rios, Sale, Peavy)
Oakland: 3 (Reddick, Parker, Cespedes)
Mariners: 2 (Hernandez, Seager)
Twins: 2 (Mauer, Willingham)
Orioles: 2 (Jones, Wieters)
As you can see, the A's have very little depth. The only AL teams with less returning talent (as measured by WAR) are the Mariners, Twins, Orioles and Astros. The Orioles, obviously, were a fluke playoff team last year, but at least they have a top tier talent (Machado) would is considered on the game's best assets. Similarly, both Seattle and Minnesota have legitimate star power, as both Mauer and Hernandez post star WAR (5+) and would be more valuable on the open market than any Oakland player.
Of the teams with four "3 WAR" players (Rays, Toronto, Royals, Yanks), each team also has a 5+ WAR player: thus these teams are just one 3 WAR player away from meeting the "World Series participant talent distribution" criteria. In addition, a of these teams are loaded with top tier prospects would fetch more on the trade market than any Oakland player. Tampa is loaded with top tier, young, impact talents like Moore and Myers, both of whom would be more valuable on the open market than any A's player. The Rays also have a true star, Longoria, who didn't stay healthy enough to post his usual star WAR last season, but projects well going forward. Similarly, the Jays and Royals also have great young players who are widely regarded as more valuable assets than any oakland player, who nonetheless had WAR below 3.0 last season: for example, the Jay's Brett Lowrie or Kansas City's Salvador Perez. Unmentioned players like Eric Hosmer, Colby Rasmus, Jeremy Hellickson, etc., would also be among the A's most talented players, but they aren't mentioned in this inquiry. Accordingly, there is a vast difference between these four "star power + four 3 WAR" teams and the remaining teams.
The AL teams returning only three "3 WAR" players are all mediocre teams: the White Sox, the Indians, and the Red Sox (and A's). The Athletics compare very well to a mix of the White Sox and Indians: both of whom overachieved and took advantage of a division leader (Detroit) who refused to play smart baseball. The A's, similarly, were gifted games because of Texas's insane devotion to Michael Young, which was season-suicide. The lack of talent on these teams will likely lead to three front office firings in the near future: everyone knows the Indians FO is on very thin ice, the Boston situation is very warm, and the Kenny Williams circus will end within a year or two. These are three of the worst front offices in baseball.
The Tigers, Rangers, and Angels are the three real or "serious" contenders in the AL. Only these three AL teams return enough talent meet the basic talent distribution criteria to be a World Series contender. Obviously, both Tampa (Longoria, Moore, Myers) and Toronto (Lowrie, Romero) have a good chance of meeting the "WS participant talent distribution criteria" this season: several projection systems project Tampa and Toronto to meet those criteria. That's five teams who project to be "serious" contenders based on basic WS participant criteria and an empirical analysis regarding returning player production. Additionally, both New York and Kansas City project to come close to the WS participant criteria, needing to only to add one 3 WAR player.
Oakland doesn't project to meet either the star power criteria or the depth criteria. The only other teams that fail to project to meet either criteria are:
Red Sox, Indians, White Sox, Astros.
Those are some lousy MLB teams facing troubled times.
It's easy to argue that Oakland has far better MLB talent than Houston. You can make a very fair argument that Oakland's depth overcomes their lack of star power, such that they are more talented than Seattle and Minnesota. Similarly, you can make a reasonable argument that our A's have more youth and more momentum, chemistry, etc., such that our team is rendered more talented (as a team) than the Red Sox, White Sox, and Indians.
Beyond that, it gets tough to prefer Oakland's talent over any remaining AL team.
No reasonably argument could be made that the A's are more talented than Detroit, Texas, LAA, Tampa, or Toronto. Only a rosy-glasses argument could put the A's ahead of the Royals and Yanks. There are only 15 teams in the AL. The most objective assessment is that Oakland is a "bottom 8" team in the AL, as it is really hard to argue they are any better than the 7th most talented AL team.
So if you look at the White Sox roster, and think "they should trade their top pitching prospect for a DH/C going into his age 30 season who has never sniffed an all-star game," then I understand why you'd want to compete now, and therefore, why you'd want to trade the Oakland's best SP prospect for Jaso. Similarly, if you look Boston, Cleveland, or Houston, and think, "yea, go for it," then I understand why you look at our roster and have similar sentiments. But obviously, the A's lack both star power and depth, they do not project to be in serious contention for the AL crown or the WS crown, and the roster is filled with low-ceiling, low variance players who are unlikely to transcend their career trajectories
In short, you guys are crazy, this team is no better than the 2011 As. Beane has become a caricature of the "statistically savvy" GM.