We need legal protections, not good feelings from these carriers in their positions of power.
[1] https://www.extremetech.com/mobile/234186-t-mobiles-new-unli...
[2] https://arstechnica.com/tech-policy/2016/08/eff-accuses-t-mo...
I used to have a Kyocera 7135[1] on Verizon with Minutes of Use(!) for data long before any unlimited data plan existed.
This was a device that didn't support cellular data in the traditional sense so they couldn't bill extra for for it.
Once the Treo 650+ started rolling out they started coming out with the $50 data plans. Mysteriously everyone with a Kyocera 7135(including myself) started having "issues" where those devices wouldn't authenticate on Verizon's CDMA network. They offered a Treo 650 as a replacement with a promise no plan change.
Of course, plan change and $500+ bill the next month as it moved me over to a per-KB data plan.
Fought them a long time on it and eventually had to give up and pick up the $50/mo extra. They weren't allowing Kyocera 7135s or Minutes of Use plans any more.
Found out a while later that everyone else on HowardForums hit the exact same thing and yet other CDMA providers outside the US had no issues the the 7135.
Verizon, ATT, T-Mobile. Take your pick they're all going to probably try to screw you one way or another. Although I'll give that T-Mobile tends to better about what devices they let you bring and what they open their network to.
Either OP didn't know (which is fine) or didn't care but wanted to try and make a comment out of it (which isn't good).
Tell ya what, though, were my mind not already made up on NN, your sanctimonious, self-righteous post would drive me right to the arms of those you oppose. You will feel that you have righted that egregious wrong on the Internet, but you will have changed no minds.