I'm not using an ISP that prevents me from accessing perfectly legal Internet services. No matter how they want to brand themselves, today's telcos are ISPs, no more, no less.
When shopping for cell phone providers, our considerations are 1) complete Internet access, 2) coverage, and 3) cost. T-mobile could charge $5 a month for unlimited usage, but if they can't satisfy requirements #1 and #2, then #3 is moot.