It doesn't help when you need to target DX9 cards that only have OpenGL 2.1 drivers.
Thus you only drop support for computers with only Intel GPU and processor older than Sandy Brige. When I consider how many app developers drop support for older iPad/iPhone versions that are much more recent than pre-Sandy-Bridge CPUs and hardly anybody complains (the same is, of course, true on Android), I really have difficulties understanding where the problem is.
However, it does not change the fact that many of those systems are only 2.1 capable.