Because you realize that it may annoy some people, but you still choose to do it because the perceived gains are bigger than the perceived costs. ;-)

It's okay in my book. ASETNIOP and particularly its Colemak-based variant are an interesting addition to the layout flora. Not exactly my cuppa I believe, but interesting!

Far more annoying is posting images as attachments instead of in img tags. Grrr.

I was having fun playing around with asetniop some years ago, it's fun, but makes more sense on a touchscreen or a place where you only have have space for a tiny keyboard I think. It's so much faster to type on a full keyboard otherwise. On a phone I'm not really convinced that it's big enough to comfortably write like that, but on a tablet it probably makes the most sense.