Not sure why there is an assumption that everybody likes 68F with miserable fog. Some people actually like 80-90F temperature. I do. 90+ is too hot sure, and I get that PHX is 100+ for 3 months. I like to be able to walk outside in a tshirt at night, instead of wearing a down jacket. I live in the Bay area and it's far from perfect weather. I can only live in the East Bay where there's actually summer temperature (80+F outside in the day time now and I love it). Living in SF would be pure misery to me. I would totally consider moving to PHX, but I first have to convince the wife. :)
I'll take 90 degrees with low humidity over 80 degrees and muggy _any_ day of the week.