First of all, it would be illegal to move all porn to one common domain suffix.

Who gets to decide what is considered porn and what is not? Porn falls under the legal auspices of protected "free speech".

Secondly and most importantly, the concept of "net neutrality" is government intervention and increased governmental control over the internet.

It is a very bad idea and should not be supported by the public. It is the public who will be screwed by any "net neutrality" type legislation.