In short, those who do thse terms and spellings do so for the sake of fun...and I see nothing wrong with that at all.
That was an interesting contraction of the words "use" and "these," don't you think?
On a more serious note, your post was very well stated, and you made some excellent points.
I do think that the "X" has it's place. Much like the Black Mass and the Infernal Diatribe, treating the terms Christ and Christian in a deragoatory manner can be liberating.
People have good reason to be angry with the Christian Church after all, and the releasing of such pent up anger, even in seemingly insignificant gestures as crossing out the Mad Redeemers name, can help one to move on to bigger and better things.