So is the NFL, although that is a legitimate sport, too. There is some legal advantage for a professional league to be called "entertainment" instead of "sport", so that distinction on it's own doesn't have a lot of meaning. It's easy to see the difference between the NFL and WWE in terms of legitimate sport vs scripted outcomes (and as much as conspiracy theorists want to whine about the NFL being "fixed", at worst, the league has their thumb on the scale in the NFL as opposed to predetermining the entire outcome beforehand in the WWE).
No offense to any pro wrestling fans here, of course. If you like that, that's fine. It certainly can be entertaining. Just don't kid yourself into thinking the outcome isn't scripted from start to finish.