Oh yeah, my post wasn't about PNaCl at all (I wasn't even thinking about PNaCl when I wrote it). It's very clear to me that wasm is a superior design compared to PNaCl, and I'm glad history went the way it did. :)
I was talking about about the sentiment that byte-code in general isn't necessary/feasible/desirable for the web.
Here are some example of the sentiment as I remember it. There was a lot of skepticism that it would be possible to design something that would be a better compilation target than JavaScript while still being fast, portable, and properly sandboxed:
https://news.ycombinator.com/item?id=1893686
https://web.archive.org/web/20101126142151/http://www.aminut...
https://www.infoq.com/news/2013/05/javascript-browser-byteco...
Issue (1)--the forwards compatibility story--is the tricky one. Was it necessary to have asm.js as a stepping stone, or could we have gone all the way to Web Assembly from the beginning? I don't know, and we might never know, but having asm.js around for browsers that don't support wasm certainly doesn't hurt.