While this is a very good point to raise, and I might have done well to consider it when I finally broke down and got a mobile phone, my thought process ran a little differently:
I searched through "reviews" of various mobile service providers, and who would have guessed that the vast majority of reviews are strongly negative? What this taught me is that there are some categories of services and goods for which most people, for the most part, are ambivalent.
I would not generally think to myself how much I love my utility companies (although admittedly, I really have no choice regarding their selection anyway). But my ISP? I have choices on that one, and I can tell you from personal experience, just like a phone service provider, either they do what I want, in which case, congratulations to them, they did what I expected them to do and I am not angry -OR- they do not do what I want in which case I am going to be all kinds of fired up and angry with them and voice my opinion to whoever will listen.
According to those ratios, only 1 in 3 customers love verizon. The other two obviously hate verizon. But it does not consider the relatively large segment of their customer base who do not *care* about verizon enough to rant about it online. The most vocal group is always going to be the people who are extremely displeased.
Seriously, my experience reading reviews taught me that while a lot of people do have certain preferences for their mobile phone service provider, for the most part, everybody hates every provider they are not currently paying, and in a lot of cases, also hate the provider they are.
Moral of the story? Just as filtering out negative reviews will not help your customers (you listening, newegg?) find what they want, if you really want to figure out which provider is the "best," you have to understand that most people do not feel strongly enough to say anything at all. Which means that for the most part, any of these companies are actually doing a pretty good job.
Disclaimer: My service is provided by T-Mobile right now, and am not at all dissatisfied with it, and while I can think of ways to improve my experience, I really do not ever think I would say to anybody that I love (or even like) T-Mobile. They do what I expect them to do, therefore I do not hate them.