Aren't we comparing apples and oranges here? This is the O Beta. I'm sure O will be supported on the Nexus 6 once it's officially out.
https://support.google.com/nexus/answer/4457705#nexus_device...
The situation is pretty complex but the support libs & play services are available on virtually all devices (API 9+ IIRC, but anything older would not be able to run most modern apps).
As an iPhone 5S user, I don't feel like I'm disadvantaged at all from having a phone that is three generations behind.
But I guess that's up to the developer anyhow.
Thanks for your reply. (A few of my friends also use 5s and they also feel it's still pretty okay.)
https://9to5google.com/2017/03/15/nexus-6-android-7-1-1-down...
(Not letting google off the hook here. What they're doing isn't great and they should do better. Just saying your statement isn't entirely correct)