In reply to David Anderson.

Bingo. This is the problem. Maintenance, bug fix and security patches for previous versions.

This model works for something like an iOS, Mac or Windows app where v1 will run like v1 for a very long time and isn’t powering a web site. But when WordPress releases an update that breaks v1 or a security flaw is discovered in v1 and you are on to v5 what do you do?

WordPress plugins are an entirely different beast to desktop or mobile apps. You really want users running the latest version so they are already running the most up to date code with the latest bug fixes and security patches… and maintaining this across every major version that you have released? That sounds like a nightmare to me.