No, he's as bad as the rating indicates. Looking at his results, he has never beaten another player in a sanctioned round. His wins are from solo MPO appearances. Anytime he's had even one other competitor, they beat him.
But honestly, I don't see the big deal. Pro Worlds has rarely ever filled, so the notion of a low rated player participating isn't new. The few times it did fill were only in the last few years when it was still combined with the Masters (which was part of why they separated them). If it were a matter of this 750 rated guy playing instead of a 1020 rated player, I could see the argument against allowing him. But they had tiered registration in which everyone invited with a rating over 970 had anywhere from 2-6 weeks to sign up. If there's a 1000 rated player sitting home frustrated that Mr 750 is in, it's his own fault.
And it's not like Mr 750 is going to be gumming things up. He'll be in a separate pool from the contenders and won't get anywhere near a filmed card except as a spectator. He's a donator, no different than any of the other 60-some odd players in the field who are rated under 970.