This medal has two sides. You only look at the backward compat issues. A developer or maintainer can be seriously hindered in two ways:

• Maintaining backward compatibility preventing use of new features
• Future compatibility preventing support for older perls

The step you describe here is most likely a stepping stone to implementation of new features that are only possible in 5.12 and up.

If you depend on a module that works FINE on the current (old) perl and does not have a security issue, why do you expect the author of that module to support 13 year old perl builds? Seriously, you are just saying that this old perl is *more* important than current or upcoming builds. What would your argument be to someone complaining that this module does not work on perl-5.37.8 with the features it promotes?

There are numerous reasons to stick to old perls, as there are numerous reasons to require a minimum version in production environments (to me that is 5.014002), and there are also numerous reasons to draw a line and require a minimuum version just to be able to go forward and support the current state of affairs.

For me the coin mostly drops in supporting old perl versions as my modules are quite high in the CPAN river, but I won't rule out that someday, I will also raise the bar to make development easier.

One more addition: stating a minimum version to authors that test their distro on all supported versions means they also need access to that version. Not all developers have 500+ prebuilt perl versions available. Sometimes you can ignore the minimum version and just build with the version you have. Sometimes you cannot.

merged edited addition: If an author states a minimum version, it might be the lowest version he/she has access to for testing. You might get away with an older version, but the author cannot guarantee it. YMMV. Additionally, they author might find a feature compelling enough to require the version it was introduced in. The end-user that still wants to use their module might be able to rewrite those to something supported in the version they want to support (like $a = $b // $c → $a = defined $b ? $b : $c;).