I agree with your viewpoint for different reasons.

I like RubyMotion _because_ it is for iOS. I've developed for Android and iOS and much prefer iOS.

I dislike RubyMotion because the current debug tool chain/error messaging is so weak. I can't jump into the code and fix it. Many times wishing it was open source for that reason.

So for the time being I've shelved usage of RubyMotion, and hope to return to it once the tooling improves.