The justification for the removal is that Bitcoin XT is an altcoin, and altcoin discussion is not allowed. [2]
[1] https://www.reddit.com/r/Bitcoin/comments/3h424p/why_is_bitc...
[2] https://www.reddit.com/r/Bitcoin/comments/3h424p/why_is_bitc...
Bitcoin is designed to be fought over and amended, it's built into it. Software is never complete and XT is not an altcoin.