That's how 3ds max's hair works. Select the polys, grow the hair (add modifier), change any parameters you want.
Then you can brush the hair how you want it styled. Pretty nifty.
It's all non-destructive too (as long as you don't collapse the modifier stack), and you can grow multiple hair styles on/across polygon groups. It's fully dynamic of course.
I've never understood why people say 3ds max is a hard interface to learn. It's all very neat and well organized, IMO.

Friends don't let friends use booleans.