Title is a bit sensationalist, but he makes a great point. It's ok to be a little less DRY and implement your own helper methods in the namespace of your gem rather than include the whole low-level object invasion of active_support.
It seems crazy to me that someone would build a gem that expects the user to already have Rails installed. =:-o
Well, it expects the user to have the activesupport gem installed. Rails depends on it, not the other way around. But yeah, usually if you've installed one you've installed the whole rails bundle.