In reply to Kraft.

Looking at it like any other piece of software, there are sometimes reasons you can't run the latest minor version (where format is ..). On linux distributions you see this where they backport fixes because a 'stable' release can't update a bunch of dependences just because of a security breach.

With WordPress there may be some sites running with custom coded plugins who have made the choice to stick with 4.1.x, or 3.9.x because it would cost them a bunch of money or pain to upgrade straight away. They may be working on porting but need some lead time to update parts of their code.

It's fantastic that WordPress are backporting security fixes into older versions for these situations. For those not used to the way versioning works in software it might be confusing, but I imagine 99% of users will have no issue in upgrading to 4.2 and leaving it at that.