And yet that's what every good engineer did when Spectre came out. Same with the Pentium fdiv bugs, and same with a host of microcode bugs that come up all the time.
Not my business to decide what you think is reasonable. That's just what happens in the world, and what (in my view) good engineers sign up for.
The choice is between letting hardware be not finalized and letting that force software to be non-finalizable, and letting software be finalizable and forcing the hardware to be finalized too. I like latter more. Finalized hardware is better by itself as well.
If you buy a car and the airbags randomly deploy, would you consider it reasonable for the manufacturer to respond "oh, yeah, that'll happen if you drive it on roads rougher than polished stainless steel. You should only be driving on polished roadways"?
If this requirement was known to me before I bought, sure.
I think that this is a bad analogy to hardware, though. Polished steel roads are unreasonable to ask for, but bugless processors are reasonable to ask for.
They may not be impossible to make, but they don't get made. And I guess you think Microsoft has been putting bugs in Windows for the last few decades just for something to do, or was that also the influence of alien gods?