> the only cross platform UI experiment that has 'worked' on any significant level.

Users do not care about cross-platform compatibility, at all. They only care that it works on their platform. As developers, we should be cheering for a diversity of widely-popular, mutually-incompatible platforms because there will be more work for developers to port the iOS version to Android to Windows, etc.

The only people who should be upset about cross-platform compatibility issues are budget-conscious managers and unfortunate OSS devs.