I guess the reason you don't have a higher score is because you're speaking the truth...
What follows now is not the majority opinion of the Internet. I will be modded down to oblivion. I know this. But I will state my argument anyway.
Corporations, with as big wallets as they do, still have budgets. To upgrade a cellular network takes a LOT of investment. It's not a simple software upgrade like taking out data "chokepoints" like with working on servers in an IT environment or something like that. They literally have to buy more and install more towers to improve backhaul on given area. There very much is a physical and electromagnetic element to this equation. (I've worked with Nokia. I've worked with T-Mo. I know my shizzle.)
If everyone would rather have super strong signal but super cruddy phones (ala Verizon before 2007, exception being the Razr), then live with that.
There is a balance between getting nice phones and having good signal. Some of the loud critics of ATT and/or Verizon need to get their facts straight. They're doing the best they can while trying to maximize their profits and keep their incomes steady.
Yes, ATT coverage sucks in New England and California (geek havens), while it's amazing in the southern US (they were formerly Southwestern Bell Corporation, so this would explain things...) Believe it or not, Verizon actually has quite a few dead spots around where I live, Texas...