why do people always bring up this point? you can't compare the situation of WP7-8 to WP8-10. They changed the kernel in W8 so there was no chance that (all) the WP7 phones could get the update. From 8 to 10 there's no kernel change (well, not a "whole new" kernel anyway) so there's no point in leaving WP8 behind.
also: we use W10 already on our W8 phones
I can't speak for others but I'm jaded. Kernel change or no kernel change, no one, especially me ever dreamed WP7 would end. That is to say, it would end because the platform on which it is built had no future. Nor did I think the reason would be the "direction we were headed isn't sustainable." Microsoft "pitchman" Joe Belfiore told us my WP7 would be able to read my boarding pass, look at my current location traffic and such and determine if I will make my flight on time. On that alone I moved my entire family from android to Windows Phone 7. There was this other story about choosing seats in a plane complete with a demo. Yes! I told my family, lets get to WP7. Well, none of that ever materialized. I bought the 1a.m TV advert for the
Ginsu knives that cut leather boots and I am now the last Windows Phone hold out in my house. I'm jaded.
So what were we doing the entire time? Beta testing for this current kernel? Again, I'm jaded.
I would say something akin to Windows for phones 10 is running and its more likely than not, this will get completed. But I won't ever trust to that degree again. Been there, done that, got the tee shirt.