Why would it be "against the rules"? Anything that doesn't exploit bugs like old Nozdormu combos or the one that made the game crash for your opponent, is perfectly legal. Nerfs only address balance issues, if something's giving a class too much of an advantage.
And as far as unfairness goes, there are many things worse than Mozaki combos.
I don't know what class/deck you've been playing. But if you just "sit there till turn 8+" without getting close to beating your opponent, you are asking for such things to happen. If you stuff your deck with board clears, removals and heals and basically let your opponent do whatever he wants, then you are supposed to lose to such combos.
I completely agree with you. Losing against ANY type of deck should automatically ban that set of cards. Until you become a better player and think about playing similar decks, but the point is that you shouldn't lose, ever.
Another day, another poorly performing deck someone lost by once and, instead of posting it in the salt section, makes a new topic because he thinks it's "against the rules" and goes on an all-out to attempt to counter it.
If you can't win against a deck that "does nothing until turn 8", maybe the one silence isn't your problem.
Let the Mozaki mage have fun for one game. It's a really poor combo that rarely pulls off.