In order to be an Olympic sport, a sport has to be developped in all five continents and with a reasonable number of competitive nations or at least nations having an important interest in the sport. I don't think squash generates so much interest worldwide but I may be wrong. One thing is sure : In France not many people bother about squash, it is more seen as a top executive's entertainment than as a real competitive sport...
I'm from Africa, and I don't think badminton can be regarded as being well developed there !! I think only South Africa (maybe Mauritius) has reasonable interest in it. In Zimbabwe, I think there were about 300 players, mainly in church hlls with low rooves In Southern Africa, Squash seems to be a lot more popular than badminton
It's true Africa is the continent where badminton is the less developped... I think Nigeria has quite a lot of badminton and good players in fact, but unfortunately no budget to travel to international competitions... In general, the main problem of african badminton is lack of funds!
About squash, though it is only a very secondary sport in France (more as an entertainment as I said before), I think we still have some world top 10 players... there musn't be a very high level of competition in the world!...
it is more popular in HK & UK. squash courts can be found in mnay sports complexes in HK and secondary schools in the UK have regular matches. squash however is not popular in the US, in the US they play racquetball which is also played in a room (larger) but with a bouncy ball. as a squash player, i find squash more interesting to watch. racquetball isn't popular in other countries as far as i can tell.