It's unfortunate that you felt attacked, because I didn't read the article that way at all. I'm neither a fan of JS nor particularly WASM, and I read the authors article as quite supportive and appreciative, and pointing out a potential area for improvement / documenting experiences -- and I'd love your thoughts on it!

To me, it broke down as:

(1) SSA form would allow for substantially simpler compilers. Adding block/loop parameters while maintaining support for locals as an extension doesn't address that, as compilers would then still have to implement full support for both modes of operation.

(2) The magnitude of the performance impact of this design decision.

I have some limited experience in compiler design but not enough to really have an understanding of the implications.