It’s obviously not black and white. I’ve worked on bigger, more mature, products where not giving all users access to the latest features was unacceptable. And I’ve work on products where dropping an old version early only impacted like 2 users and it was acceptable. And big companies where it was okay to let ild versions lag because the model and api layer was super stable. Ultimately it’s a product decision not some unquestionable dogma and there no reason engineering can’t contribute to the discussion. It just turns out that the last two major versions is a good rule of thumb for most scenarios. It works very well in practice.

I agree that truthfully we're not talking about excluding those users, but only preventing those users from upgrading to the latest version of the app. But for lots of businesses those two things are viewed as effectively the same, because they believe they are adding value to the new version of the app that will result in greater user stickiness and direct or indirect revenue opportunities.

Honestly I'm thrilled anytime I'm working for a client that has a iOS(-2) rule versus an iOS(-4) rule.

Figured you were questioning dogma, so I also wanted to continue the conversation explicitly.