They are still talking about the MA900 vs X1. It's still on topic.
If comparing is so bad, then maybe headfi is too much for you, as topics will always diverge a bit here and there.
Also, separating and creating various threads on the same headphone is just going to split the focus, and oversaturate the forum when talking about the same headphone. Threads like that tend to get merged, because there is no point having 4 threads for the same headphone.
X1 thread, X1 appreciation, X1 comparisons, X1 review, etc. All these things can be talked about in one thread. I don't understand why it bothers you so much. You're free to ignore posts that don't sound happy all the time or diverge from being fully X1 focused. In the end, the main point (the X1) will come right back to focus.
People are coming to this thread to read about the X1. Whether its comparisons, strengths, weaknesses, its all here. Just because someone brought up the MA900, doesn't mean he has to go post somewhere else. It will still comparing what he felt the comfort of the MA900 was relative to the X1. A minor post too.
No one is bashing the X1. You're arguing about something trivial. If if bothers, why not make an X1 appreciation thread where you can set the rules, like no debating, no comparing, etc? Its happy X1 posts all the time. Though, honestly, that doesn't help anyone, other than those that just wanna gush about a headphone 24/7. This thread is overwhelmingly positive as is, and when someone says something on the contrary, he should go post somewhere else? Come on.
More comparisons to the X1 would be great.
As for me, I'm overly critical when it comes to headphone faults. The thin pads and headband on the MA900 are a minor pet peeve I have that i absolutely want to rectify BECAUSE I love the MA900 so much. I want to make the comfort even better, even when it's already amazing.
For the X1, all it really needs for me is for the sucessor to have easily replaceable pads, more extension for larger heads, and better stock cable, though the latter is fixed easily buy buying your own replacement.