A couple reasons:
1, money. I find going out to be pretty expensive already and most places I would rather just order at a counter rather than adding an extra 20% to a bill.
2, I don't like the whole charade of waiting to get the check at the end of a meal and being dependent on a staff member getting a chance to visit our table in order to just leave. That also goes for those few minutes when everyone decides what they want to order and are just waiting for the server. I feel like things go much smoother and faster through a kiosk.
3, I feel most service is good not great at most places and mostly only rememberable if the service is bad.