Things that irk me:
We’ve already seem this phenomenon with libraries and frameworks creating their own markup patterns that are less robust than their native HTML equivalents.
The worst of the problems that arise from this situation is that it teaches people to think and work framework-first. When that happens, the hard-won, baked-in interoperability and, importantly, accessibility of the platform is thrown away. It’s a compounding problem, as well: The more people don’t use the elements made available to us, the more the notion exists that they’re irrelevant
Jim Nielsen’s post on Web Languages as Compile Targets is good reading that puts these concerns in context and suggests a way forward.