1. Most restaurants which cater to groups add a gratuity at a specific size such as 6 or 8 people. It's generally made clear at the time the reservation is made and is noted on the menu. This leaves people who don't like it, free to dine elsewhere. Same sort of things with split checks (one check per party, up to the host to pay or collect).

2. Rarely and typically only in locations which cater largely to people from countries where it's the custom to include "service" in the final bill, have I seen restaurants do it to all checks. Miami is one of those areas. It's not that the visitors are cheap, it's just that they are used to service being included, so they leave a very small tip for great service and that leaves the staff screw*d.