Why shouldn't you jump and do tricks in surf if you choose?
I think if we have to explain it to you, you're probably not going to get it anyway.
But there's a difference between ramps for jumping and waves for riding. If you're in a congested zone, getting big air is probably going to put you afoul of somebody at some point. This is a general rule: some guys are perfectly capable of pulling off jumps and tricks in the zone without mucking it up for other folks. But dude: there are plenty of places to get air and do tricks, and blessed few of them where you can get good waves. If you are not 100 or even better yet 200% sure that you're not going to rain on other guys parades, take it out of the surf/congested area and everybody will have more fun. Dropping your kite or trolling for your lost board happens to everybody, but if you do it in the surf zone because you didn't nail the latest trick you're working on, people are just going to be friggin pissed.