Regarding "jumping ship", I have done that! But I left AT&T, not Windows Phone.
I can tell you after many years of dealing with AT&T, they are 95% of this problem. They prevent the manufacturers from updating phones without their (long-delayed) blessing, and the only updates and support they provide are those which are to their advantage, not the customer's.
I once owned an AT&T Samsung GS2, which was probably the last in the world to get Jelly Bean, due to AT&T's behavior. When they finally delivered the update, all AT&T GS2's became unreliable - random reboots, extreme battery drain, missed calls. For 2 whole months, the AT&T forum was ablaze with complaints, but the company wouldn't even acknowledge the problem. Every caller to tech support was told, "never heard of the issue, try a factory reset".
Yes, Apple has the clout to bypass the carriers, but iPhone has its own ton of issues, including lockdown, crude interface, sky-high price. I owned one, and won't go back there.
So in the future, I'll buy my own unlocked Windows Phones, and use a pay-as-you-go GSM carrier. T-Mobile has some good offerings, as well as a couple of MVNO's that use AT&T.