Banned Words and Phrases: Holiday Gratitude Edition

Emily writes (once again):
As longtime readers will know, I sometimes ban words and phrases. Though I find many non-standard uses of the language to be useful, lyrical, fascinating, or all three, others are just irksome. Here’s one that’s on the rise, and at the top of my current list of irritants (aside from the economy, short-sighted capitalists generally, and the futile war against our brute natures): abbreviations of the short, concise, one-syllable word “thanks.”
I’m used to (but that doesn’t mean I accept) the sign-off “thx.” To me, it conveys a lack of complete thanks, a partial, lackadaisical hiss. The sound it makes in my mind is the insincere, singsong “thinkssss” that workmates we’ve all known like to say with a scrunched-up smirk and bad intentions. I have a feeling that the brilliant David Shipley and Will Schwalbe, whose book Send: Why People Email So Badly and How to Do It Better I read recently and loved, would not approve of “thx.”
Now I’m seeing “thnx.” “Thanks” has only six letters. Even the silliest abbreviations are fine with me in instant messaging; that’s a fun puzzle of a medium, time is of the essence, and within it I require neither punctuation nor official spelling. But in email, especially business email, seriously, spell out “thanks.” Thanks!