I like the Quality (not Qualified) Start stat a lot, because it is a measure of consistency. You throw a quality start, you have kept your team in the game and given them a chance to win.
If you take two pitchers with otherwise identical stats for the season, but one has 20 quality starts and the other has 12, I'll take the 20. The other guy got his stats by throwing some gems and some stinkers. I much prefer consistency.
Back when the stat was first publicized, yes, the six inning minimum was criticized. It isn't any more. Six is the new seven.