It's not google's job to help tubes or webmasters or brands or be against them, their job is to deliver what people want, if they like tubes g gives them tubes it's simple as that. The only thing that they have to do is to ensure that they don't help fraud, infringement ect. and obviously they are not doing a very good job with that.
If they start punishing entire domains based on huge amount of complaints then they will actually do their job in ensuring they don't support infringement, apart from that their algorithm is doing just fine, they give surfers what they want, last time I checked search engines are supposed to serve the users not the website owners, adwords is what servers the website owners, some people fail to realize that!
ps surfers in us and uk really like xvideos
