Users in more rural areas, I can understand lower ratings from, as the signal, in general, becomes more spotty, but AT&T isn't alone on that. T-Mobile and Sprint both suffer pretty heavily in rural areas. Verizon isn't in the clear either, as I've hit a few dead spots myself. (Please note that I'm mainly talking about North Carolina area. All I know of other areas is what I've seen in coverage maps.)
Every carrier has it's own folly. Depending on the area you're in, what phone you have, or even what the reps in the local stores are like can change your opinion. Personally, I've had all four major carriers, and a long, long time ago my family was on U.S. Cellular (I can't say much for this, and a lot of things have changed, but my mother was always pleased with them). Alltel was always my favorite, that is, until we got swallowed up by Big Red. To be honest, I've never had any major problems out of any carrier. At least nothing I would rate a carrier badly for.
I was pleased with Sprint, their customer service, and for the most part, their coverage. I can say the same for AT&T and T-Mobile (thus far). I've dealt the most with Verizon over the past couple years, and have yet to have a single problem out of them. What I believe it boils down to is customers having the wrong carrier for their area for one reason or another. It could be anything from jumping ship from another carrier to get an iPhone, poor coverage in the area to begin with, or the carrier not expanding networks fast enough in a particular area, etc.
What ever the reason may be, if you aren't happy with AT&T or whatever carrier you are with, maybe it's time to start browsing again. Put yourself on the market and take advantage of those 30-day return periods. Take a phone home with you, check out the coverage, speeds, whatever it is you're interested in, and go from there. Even if you're not out of contract yet, being with a company that you're happier with may be well worth eating an ETF, at least in the long run. In any case, I wouldn't let a single poll make up my mind for me. If you were interested in AT&T before, still go check them out. You've got nothing to lose.