It would be one thing if Rails was the only gem that depended on ActiveSupport. The problem is that other authors use it because they initially expect their lib

It would be one thing if Rails was the only gem that depended on ActiveSupport. The problem is that other authors use it because they initially expect their library to be used with rails. And then, if someone chooses to use the library without rails, all of ActiveSupport must be brought in as a dependency (which is ugly). I think DHH's aesthetic intention with ActiveSupport was for it to be used by Rails, not used by a random assortment of gems throughout the Ruby ecosystem and misunderstood by a lot of people. FWIW, ActiveSupport is one of the main reasons why I stopped using Rails a while ago. The other was that version updates typically have a LOT of API changes that make staying up to date quite a drag (or source of tech debt).