Ironically, this was a better proof of transparency than what most "problematic" people would subject themselves to. If any vanilla oligarch wanted to be in those circles, he would just pay some squeaky-clean individual to be his stooge, and then make it known, after registration, who the real power is. Sunde could have configured himself as a freelance consultant to his friends, and he would not have appeared on any radar. This would have made his business work, but it would not have advanced the perennial conversation about ICANN's original sins, which have become more and more untolerable with the years.
ICANN were pretty stupid to just veto his admission. That's not how you deal with institutional critics. They could have simply brought him in, then informally and formally vetoed anything he wanted to do. They have experience with people who tried to blow up things "from inside" in the past, so clearly they've developed countermeasures ready for that scenario. Or they could have given him something, enough to behold him, so he'd have an incentive to stay in the tent and piss outside rather than the other way around.
This attitude proved Sunde is fundamentally right on the subject matter, like him or not as a person.