I've never understood all the backlash AT&T gets. I have nearly perfect 3G signal 85-90% of the time. I live in Southwest Florida currently, and before that Utah. Both places were good to excellent in terms of service reception.
Certainly there are parts of the country where users can't figure out what the fuss is about.
From user reports, it does seem that AT&T works really well in Florida, for example. The flat wide-open space no doubt helps.
This article states that AT&T's rep is so tarnished because the loudest voices are the ones in the worst markets (Tech bloggers in San Fran and NYC)
True, even AT&T has said that NYC and SF are bad spots for them. But it would be disingenuous to say they're the only places and are causing all the bad PR.
Most people don't read tech blogs, but they do use word of mouth from other users and friends. For instance, where I live in the foothills of NNJ, AT&T phones are useless inside some restaurants, and dropped calls happen while driving... and everyone knows it.
The problem is that AT&T sucks in a lot of high profile areas such as those you mentioned. Part of that is AT&T's fault, part of it is zoning issues that makes it so it takes 4 YEARS just to put ONE tower in a place like SF.
Jobs said "three years", and it's typical handwaving and dissembling on his part.
No one has to "put up new towers" in places like San Francisco. It's not like they have to buy land in the middle of the street. Or even pick out the highest buildings. All the best locations were grabbed long ago by either other carriers or third party tower companies that lease them.
Even AT&T has never made such an excuse. Instead, they have publicly admitted that they simply didn't plan out their network well enough.
AT&T started with GSM/TDMA for 2G, using sites that were spaced for that, and thus were not optimized when moving to UMTS/WCDMA for 3G.
(The number one reason why Verizon does so well in comparison, is because they planned their network for CDMA from the start. So going from 2G to 3G was simple for them.)