Trolling?
You do realize that these pro's, while more than happy to help newcomers, are just trying to play the game and aren't there specifically to help you, right?
Like, it's very hard to gauge someone's skill level before a match starts, usually it takes the entirety of a match to figure out that maybe this guy doesn't know what they're doing.
In random matchmaking at least, they have no idea whether the person they're fighting is a noob, a player of their level, or a tournament winner, so they give it their best from the get-go, and with fighting games that usually means going in hard and not letting up.
What exactly do you mean by trolling?