Nah, it was more than that: The patches do things like add the garbage MSR writes to the kernel entry/exit points. That's insane. That says "we're trying to protect
the kernel". We already have retpoline there, with less overhead.
Yes, but as far as I know Linus has made no comment on the microcode patches, so mm-vorticesoft is probably referring to the Spectre patches in general.
When I read it I believed that Linus was implying that the suggested mitigation was so insane that it seemed like Intel MIGHT be hiding how broken they believed their hardware was with such over-the-top reactions. As well as indirectly asking if they believed the currently accepted mitigation method (retpoline) was considered ineffective.
His overall point was a bewilderment at the incompetent and non-sensical patches that were being given as "fixes" in this issue. Linus was pointing out a particular instance of that, but this news and other behaviour from Intel seems to indicate this is part of an endemic, cultural, administrative issue inside the company.