Tips and service in America, do they deserve it?

Vie been a few places around the world and out of all of them the worst service was in AMERICA...I didn't feel that i should tip or pay service charge! The worst was when i was in Miami, i couldn't believe it! I myself work in hospitality and have worked in Australia and London! The best service i got was at our hotel restaurant in jamaica, everywhere in thailand and Tapas bars in spain...