I'm down with ditching it in favor of commenter. But I do see why it exists. To commentate is to continuously comment on something. The person's job is to commentate, not just to comment.
Unironically, I totally agree. Commentator is dumb and redundant, commenter is the superior alternative.
Just because you do it for a living, doesn’t mean that it’s a different title; a carpenter doesn’t become a carpentator because it’s a paying job. A pilot doesn’t become a pilotator when they get paid for it.