Xamarin - Disadvantages

I suggested Xamarin for a client and I agree that he worried about the disadvantages of Xamarin and decided to go to native app by Java and Object-C for his apps:

1) For Apps of UI heavy, in Xamarin I would still need to build separate UI code bases. The common code that could be shared is quite small
2) Limited Ecosystem/Community compared to Java and Objective C. This slowsdown development if you need certain help
3) App overhead. Xamarin adds a few MB overhead on the installer
4) Xamarin add another layer of potential bugs besides the native platforms.Debugging might be challenging at times
5) License fees are too high