Not true at all. I could have easily gone with another phone or carrier. My choice was PURELY based on my intended use.
I don't want to keep beating a dead horse, so I'll just say I disagree with your reasoning. If you had chosen a different smartphone on AT&T, you would have still paid the $30/mo for unlimited data (unless you cheated the system with the dumb phone data plan, but I'm assuming everything above board). If you had went with another carrier, TMobile, Sprint and Verizon were all unlimited data plans for $20-30 a month then. There were no throttling, no hard limits on data with regards to smart device plans.
The only thing that I really want to know about AT&T's throttling of the top 5% of users is how often that 5% is redefined. If you throttle the top 5% and then the next month throttle the top 5% from that month, now you're effectively throttling the top 10%. Then it just continues and because you redefine what your top 5% is every month, the data usage will continue to go down an encompass more people in the top 5%. I'm kind of afraid that's what's happening and why more people are being affected.