I love Disqus! I think it's the best commenting platform by far. Ads have always been optional. If you just want to use their service for comments, they let you do that...for free! If publishers want to use Disqus to make a little extra money, they can enable ads.

Whether or not free Disqus accounts will always have the ability to disable ads remains to be seen, but right now they aren't forcing ads on anyone.