Ouch. Did you read https://matrix.org/foundation or https://github.com/matrix-org/matrix-doc/blob/matthew/msc177...?
I'd agree that skepticism was warranted if we hadn't split out the Foundation and the protocol was de facto controlled by Element. But instead we made damn sure to create the Foundation independently and frankly protect it from being sabotaged by Element or any other commercial entity building on Matrix. To suggest otherwise is pretty insulting to the other Guardians/Directors whose only role is literally to oversee and ensure that the protocol isn't sabotaged by commercial entities.
This is very different from Microsoft's model.
IETF is one of the best standardizing organizations out there, I'll certainly give you that. They have fairly transparent process, and a really good track record when it comes to creating robust protocols.
Thing is, I don't see why Matrix.org would have any more or less "cachet" than WHATWG, or Khronos Group. In the end, the identity of the standardizing org doesn't really matter too much. What matters is that the incentives of the standardizing org are aligned with those of the community.