The mitigation does not prevent a particular class of bugs, it prevents a particular class from being exploitable by turning an invisible-but-possibly-exploitable bug to a crash bug. The bug is still there, but now it has a larger impact on most customers.

That's a serious tradeoff, especially (as Linus is complaining) turning a rare bug into a crashbug doesn't allow you to detect and fix it, you need a mode where the bug is logged but the process is not stopped (and might be exploited) so that the bug can be reported, reproduced and fixed.