Altcoinstalks is not to hard to say, it write, even though i noticed that many of us take out the "S's" when writing or pronouncing, this I believe does not matter as long as the reader understands what exactly is being referred to.
And when it comes to abbreviation, I will agree that ATT is better, not just easier to pronounce or write due to fewer letters, it also makes more sense and can easily be related and compared to the top bitcoin forum, which is BTT.
But then, if the admin has made ALTT the official abbreviation for Altcoinstalks, then I see no reason why it should be changed, ALTT is still as simple to pronounce or write, including an "L" in ATT should take less than a second I believe.