So let's have fun with numbers...
1.4b Android users. 7.5% updated to the latest. That's ~105m.
500m iPhone users. 84% updated to the latest. That's ~425m.
(I'm pulling these numbers from different sources, but they're probably of the right scale.)
My only point is that there might be an argument that Android's deploying new versions on about 1/4 of the devices that Apple is, not 1/10. Which is an important distinction if your argument is that Google is failing at getting people to update their devices.
It's webdev for IE all over again supporting balls old versions.
Releases are always additive, and (to my knowledge) have never removed anything (even when they really really should have).
The only reason to target a newer version is if you need things that were actually added to the OS (like fingerprint scanning). And even there it's pretty easy to gate functionality. The vast majority of apps don't need to care in the slightest and with appcompat almost everything useful is available.
It's not like you have to make completely separate apps for Lollipop and Marshmallow the way you used to for IE and everything else.
Also, just to check, we're talking about versions and not API level, right?
And just because a lot of people wait to update until they get a new phone doesn't mean they don't care about that update. Or that handset manufacturers don't care about the update. Or that Google should stop making new versions of Android. Or whatever the author's point is...