Well that's the problem right there - you'd pay a whole 10$ and from the tone of your post, you consider that generous. The amount of people who even know or care about Android version on their devices, intersected with the amount of people who'd pay reasonable rates, is tiny.

Even worse, you need people who:

* Care about the Android version on their devices

* Would pay reasonable rates

* Stick with an older phone / don't buy Nexuses

It's not as bleak as that. There are a lot of people with manufacturer-abandoned phones that would probably be willing to shell out a modest sum to get less ancient firmware. As with everything, the economics are a question of quantity and effort. A billion Android devices enter the marketplace each year.

I think the real problem is that it is just turning out to be difficult to make a silky smooth upgrade process, the kind that is consumer-friendly enough to create a mass market. It all fundamentally starts with "hack the device" and most people can't. Maybe it's just a really hard problem because it varies from device to device and base OS version to base OS version.

What's so special about Nexuses in this regard? I find the duration of support still pitifully short on them even if it's slightly better than what some other phones manage. Whether or not people care about their version, everyone should if only because of security.

Don't have experience with that specific device, but it looks like an Android 6.0 build is available: http://forum.xda-developers.com/galaxy-tab-10-1/development/...

Why is Honeycomb useless?

You might have specific usage patterns where shows but I would say that there's anything wrong with Honeycomb but, rather, that the major problem is that the hardware itself doesn't really stretch enough to run newer Androids or newer websites/applications. I'd just keep the less resource-hungry Honeycomb installed until the hardware can no longer do modern content.

A big chunk of apps require at least 4.0. Or maybe they don't but if you have an older version you will have to use an older version of the app with less features.