Right, but the discussion is about anonymous VPN use. There's always a server that knows something - but using EC2 means it is extremely easy to tie to your id

Right, but the discussion is about anonymous VPN use. There's always a server that knows something - but using EC2 means it is extremely easy to tie to your identity through your credit card, shipping and billing addresses, etc. And Amazon is in bed with everyone VPN users might want to stay anonymous from - so EC2 is an exceptionally poor choice if you care about anonymity.