I agree on the technology. And it's not even as slow as they make it on the tennis broadcast. My wife went to the broadcast booth at the US Open and they run instant in/out analysis as the point is being played. The ball landing/zoom in graphic is just for TV. They could simply have an indicator light when a ball is out - stop play, next point. However the sports organizations are more interested in the fan experience both live and at home, i suppose understandably so.
Fans that care about the most accurate enforcement of the rules, and thus the purest form of the sport they love, are less than fans that want to enjoy the entire experience (e.g. more artificial emotional highs/lows, things for players and fans to complain/argue about, etc).