I made a 29er hardtail with a 70mm BB drop which is considered low for an MTB. But because it's a 29er (big wheels) that works out to about 312mm from the ground to the centre of the BB. The person I was making it for likes a low BB and isn't usually riding on big rocks. He hasn't had any pedal strike issues.

So it depends on the use case but I think quite low makes a nice riding bike.