I'm willing to entertain the idea that they might deserve a nerf in PvE, though even there not really because there's classes that are equal or superior to them. But they are so far from OP in PvP. So many classes are so much more powerful in PvP than a R/M, and if a R/M is the one class you can't counter in PvP, that's a player or a gear problem not a class imbalance.
Because you guys are talking about completely different scenarios. Rogues in general are OP where sieges are oneshots (mainly in lower end sieges), because first hit wins. And a rogue in hide will inevitably get that first hit off. Not really because of rogues, but just the way siege is designed. Also, at this range, people are usually not playing fotm classes like M/Wd.
On the other hand, outside of one shot sieges, there's plenty of classes that can take a R/M. They aren't more OP in PvP in general - just that the way siege was being a oneshot fest happened to benefit them a lot more than others.
RTP's advice to silence R/M is only applicable in endgame sieges. In sieges where people are oneshot and rogues are always in hide, silencing them is not an option because you can't see them. And even if you could, their CT will oneshot you anyway (and I'm not talking about all 4 hits killing you - I mean the first hit from CT kills you) and you'd be better off using a damage skill to try to oneshot them rather than worrying about silence. In fact, you'd probably want them to silence/SP you first, so you have time to immune, because if they oneshot you right away, you have no chance to do much of anything.