> I guess my question is, why is Go compelling as a source language for WASM?

I'm using WASM as a proper plugin architecture for some of my go applications. I provide an interface that allows external developers to create plugins (in whatever language supports WASM as a bonus). Then my application can then use these plugins to execute some extra functionality. It slows the application startup a little but runs pretty fast when in use, but I don't have plugins in any hot paths (yet).