It's a great target for a simple language (unless you insist on someone else doing your GC for you, which mandates their design on your language).
And it's also fairly easy to build a Wasm interpreter, or an AOT compiler.
It's also largely useless outside of targeting c/c++ and derivatives. Most code we write cannot target wasm without severe drawbacks.
But.... they would certainly be much more useful architectures and devices if they chose to cater more to actual needs rather than performance under C/C++
Not to mention the issue that bundling a GC implementation as part of your web page can be prohibitive in terms of download size.