Context, and the Limits of Statistical Reason
With some small exceptions, SABRmetrics haven't changed the actual object or basic strategy of baseball: throw ball, see ball, hit ball, catch ball; rinse and repeat several hundred times as necessary. By contrast, even fairly rudimentary advances in our understanding of basketball through refinements of box score statistics have fundamentally changed the nature of how the game, especially at the NBA level, is played.
The most obvious example is the value of the three point shot. Now, 3 is obviously greater than 2, and by an easily determined amount as well. However, until the ideas such as points per shot (most commonly expressed as either TS%, taking into account free throws, or EFG% which does not), the added value of the 3 was not at all internalized in the decisions of players, coaches or players.
As an illustration, Larry Bird is regarded by general acclaim as one of the greatest shooters (I hesitate to describe him as a jump shooter) of all time, never shot more than 237 threes in a single season. In fact in 1986 he led the NBA with 194 attempts. By comparison, last season 78 players took at least 240 3PA and one hundred and six players took more than the 194 he fired up in his league leading season. And this happened in a season where teams averaged roughly 7.5 fewer possessions each with which to launch these threes. I simply refuse to believe that Charlie Villanueva is almost three time more adept at getting a good look from 3 than the Legend. I just can't do it.
If Larry had thought 3s were a good shot, he would have taken more of them. But in that era, heck up until very recently, the thought process was very much along the Collinsian lines of "take a dribble in and get an easier look." Former players in the commentary booth can still regularly be heard to say variations of just that, not to mention Charles Barkley's maxim that "you don't live by jumpers, you die by them" (though this may be more true than not, but not for the reason implied by Chuck). Players, just like coaches and executives respond in large part to received wisdom, so if they are told that a pump fake and one dribble into a 19 footer is a better shot than just shooting the three (or as I like to call it, a Bargnani) then that's the shot they'll look to take. It's certainly a better shot to take in most open gyms, which are the real crucible for game and game-like experience for forming the skillsets of players.
So we get guys like Isiah Thomas who suddenly look terrible in historical comparison to some more modern point guards, because he couldn't shoot 3s. Well he certainly didn't shoot them much, or well. But shooting 3s was not an important skill, certainly not for a ball-in-his hands point guard. Isiah was already somewhat transgressive as the first of the modern "score first" point guards; Chuck Daly may have been a basketball saint, but he was also old school enough that he wasn't going to have his floor general lobbing up 25 footers. And the importance of the 3PG is just one area where an understanding of the math and statistics of the game have changed the performance of the game.
All this is, as is my style, a long-winded way of saying that it is impossible to complete divorce achievement from context. Many players who are doing things which are "actively harmful" are simply executing plays and taking shots they've been told are good, winning plays. Did Monta Ellis suddenly change from a conscious-less chucker into an surprisingly efficient if turnover prone playmaker? Or is he just in a situation where he is encouraged and possibly required to play to his strengths and avoid his weaknesses as an offensive player. The Spurs have long appeared to do more with less, simply because they take the useful parts of players' games and then have the players use that part and ONLY that part.
Regardless, my essential theory is this: no matter the metric or system one uses to analyze players from a purely stats-based viewpoint, you are not measuring the ability of that player so much as you are capturing their effectiveness within their given role. While to some degree these values converge, it is still an important distinction to make, especially when your starting point for discussion is "who would you rather have?" Unless Player A is Lebron James, your answer should be another question: "what else do I got?"