As far as I can see the argument is already over if the anti-XT crowd feels it is so certain to lose any fair contest that it will resort to tactics like this.
Seriously. They screamed all rational discussion about ending the block size limit to a standstill even though ~75% of the users and an even greater fraction of the miners are solidly in favor of >1MB blocks, and now that they are facing an actual implementation of a client that will hardfork to >1MB blocks they're trying to sabotage the consensus process rather than allow consensus to be decided by adoption?
At what point do they admit they've already lost?
If ~75% of the users and even greater fraction of the miners are solidly in favor of >1MB blocks, how come XT doesn't have 75% of the nodes and a large portion of the blocks aren't blocks with the XT version number?
Part of it is all the fear mongering out there from the small blocks camp, as well as just the human psychology/sociology involved. A lot of people simply won't make a decision until they see others have already decided, and the existence of Not Bitcoin XT doesn't help that one bit. It proves that we don't even *have* an accurate way for people to find out how many other people have already gotten on board.