Why would you say it's better than Objective-C? Since anything it can do has to exist in the Objective-C framework offered by Apple, it is probably equivalent.

Also, let's not forget 90% of things that make money in the App Store are games. RubyMotion doesn't seem to do much to help you with that.

In other words, for Rubyists, RubyMotion is a thin wrapper around Objective-C classes that feels like home. For everyone else, it's an added layer that provides a thin sugar coating and not much else.