I can see your point, but, as with Alex, I can't agree with it.
What I would say is go ahead and review a neo prog album, but make it clear in your review that you dislike the sub genre and that this should be taken into consideration when reading the review.
Even better, though, is that the better reviewers will put aside their personal prejudices and review/rate an album based upon the merits or otherwise of that particular piece of work.
I will put my hands up here. I am now in the top 100 reviewers in terms of numbers of reviews, and I like to think that I abide by what I said above. However, I have been guilty in one of my earliest reviews of a terrible amount of personal prejudice, and that was for Yes' Drama, which I awarded the ultimate stinker of one star.
I still dislike the album, but it is certainly not that bad, and when I have time, I will revisit that one, and uplift the rating to where I think it should be stripping aside my personal prejudice of a great band without one of my lifelong idols.
However, free speech and all, you simply cannot impose a ban or rule such as the one you are suggesting, and, anyway, we are all pretty good at spotting the trolls, idiots, and general troublemakers