You do know that a lot of those regional and MVNOs are actually partners of the larger companies right???
Yeah and? Can I use 4G with them? Nope. Do I have good choices of phones? Nope. Most of their smartphones are underpowered and are still on Gingerbread of Christ's sake. You see I can take my Verizon 4G phone pretty much anywhere and actually use it without it roaming. Can you do that with a MVNO?
Actually you can. TING allows roaming and has signed and LTE agreement with Sprint. You have a choice of phones and can take Sprint phones to them. TMO is the same way with phones.
And actually, you do realize that VZW and Sprint and Alltel still roam on each other right????? Just because your phone with VZW doesn't say roaming, in many markets you can be. They also used the words "extended coverage"
So one would advise you to actually read on many of the new MVNOs and see what they're doing before jumping the gun and claiming its not able to be done when crying about you don't have services in your area.
Actually by using WiMax and LTE yes it is 4G. And my point proves that you said nobody else has it. When in fact they do. And if you don't like your choices for service, you shouldn't have decided to live where you are and should consider moving.