I imagine Wasmer must be in a bit of a difficult place right now. My understanding is that they are VC-backed (YC?), which means they're essentially trying to figure out how to make a huge amount of money off an open standard or something adjacent to it. But then, they would have known this from the very start, so I'm not sure what they expected, or why a VC firm would even look at them as a promising prospect.
Maybe they hoped to be like Docker, where the value-add was cohesive higher-level tooling on top of all the lower-level bits. If that's the case, then WASI would be an existential threat in that it (and the tooling people are building around it) commoditizes what would otherwise be Wasmer's special sauce. I'm speculating wildly, of course, but it would at least be consistent with Wasmer's/Sirius's apparent vendetta against WASI and the people working on it.
I hope Wasmer eventually finds a way to add value that doesn't rely on constant gaslighting and white-anting the standards process.