"So long as you still live in the place yourself "

A way to game this might be to:

1) Buy a place

2) Rent out 1 room full time to someone who agrees to #3 in exchange for below market rent.

3) Rent out the other room or rooms.

This was the case at a place I stayed at in Boston - the place was a 3 bedroom apartment, 2 bedrooms were occupied by long term tenants, while the room I was in was exclusively for AirBNB.

I think rooms get far less than a full apt, even if you get the same space. Just having to deal with another person there means you can't totally relax in most places. (Like walk naked from the shower to the room.)

Seems pretty easily solvable - only enforce it for listings for whole apartments.

People might lie, but there is going to be some immediate negative feedback when people find out they've rented out a couch...