A large part of minimum qualification is because of things like the batting title, but batting average itself has no bearing on the number of games you play. It's a simple average. WAR behaves (more) like a counting stat in that regard, so it does. That's also why (to my knowledge) the 3.1 PA / team game does NOT apply to things like home runs, RBI, or stolen bases. They are counting stats, not rate stats.
I guess the point I'm trying to make is that you can't make an encompassing statement that compares players with a stat who's value is somewhat directly affected by the number of games played, then arbitrarily cut off the number of games - at least not at levels that eliminate players of interest in the study. Obviously no one is going to care about a bench player that gets 300 at-bats for example (unless they were expected to be a regular), but people are going to care about guys who are fairly regular players who simply missed time due to injury (which is largely not a reliably predictable occurrence, at least not major injuries). Jeter, Tulo, Hanley, Drew, Everth, etc would all be players that could be expected to be included.
I suppose in the end, this is more picky than a critical issue anyhow, at least in this case. It is important however when making an observation backed by stats, to do so in a manner that gives an objective (and complete) picture. Subjective opinions can filter it after that, and if all of the data is presented, those opinions can then be properly debated.
BTW, your list seems to be missing Hech as well
God, I suddenly feel like Moogy. I had better have a shower and go to bed lol.