Antonio, but nothing prevented him to contribute back to MacRuby (OS X) the required changes to get rid of the GC and therefore to not rely on deprecated technology.
Laurent frankly is underpricing his wonderful tools, and has to support himself and all those folks he's hired.
Time is finite, and no human can do all the things they'd like to do.
Modifying RubyMotion to have the right hooks for the OS X apis etc is likely much simpler than fixing up MacRuby architecturally.
Point being, people have finite time, they can't do all the things they want to. Either be nice or give him a time turning / time travel device