Current behavior:
Jenkins shows plugin X as AVAILABLE for my current Jenkins version, but than claims that

Warning: This plugin requires dependent plugins that require Jenkins 2.60 or newer. Jenkins will refuse to load the dependent plugins requiring a newer version of Jenkins, and in turn loading this plugin will fail.

I.e. it is NOT actually available for my Jenkins version - and Jenkins does not offer me an older (compatible) version to install instead!

Now naturally, this is a bug in the plugin itself - it cannot support a Jenkins version that its dependencies do not support - so I probably should open a bug report in all of the 20 core plugins that have this bug for my current Jenkins version..

BUT Jenkins should be much smarter about this:
Instead of just checking plugin X for its supported Jenkins version, also check all the dependencies. If any of those require a newer Jenkins version than plugin X itself, mark that version of plugin X as incompatible (internally), and check the next older version of plugin X if is compatible with the currently running Jenkins version.

It might also be worthwhile to only accept plugins that depend on a Jenkins version that all their dependencies also support...