I think the point people are making is that WebAssembly can't be a response to the prior shortcomings of the CLR/JVM because so many of the things being identified as shortcomings aren't (at least not in the latest versions), and so many basic features that you'd want aren't in WebAssembly.

WASM exists mostly for political reasons as far as I can tell: it's something people who work on browsers can "own", vs outsource to other older teams with more historical baggage and different backing corporations. I mean, for WASM to be technically compelling you have to buy the idea that the best way to move the web forward is to enable applets-written-in-C without any useful form of DOM interop or GUI. That seems like a rather implausible claim.