The blocking have specific effects on each other; that's the whole do X until nothing can change it routine from yuma's original resolution chain.
For me, killing each other doesn't affect each other in the same way -- dying happens last, after killing, so dying doesn't block an action from happening.
If it did, all kills would also be roleblocks.
I guess I always interpreted it that way. Killing does roleblock, and that is why it is always late in the resolution chain. So to me, dead investigative PRs (investigation usually happens last) shouldn't get a result, but that doesn't usually matter, because they are dead.
I feel like at the core here is a misunderstanding of how night action resolution works. Night action resolution is not resolve 1 category of actions, then resolve the next and so on. Night action resolution is: Find some action that could not be modified by any other action that same night. Resolve it, then continue. Only in case of conflict do you actually need a resolution order.
For an example: Bus Driving usually happens prior to roleblocking in the order. Assume player A blocks B, and B Bus Drives C and D. The correct resolution should be that B is blocked and their action does not have any effect. If we were to resolve things by category, the bus driving would still happen. In my opinion, that's wrong.
Now the other example is A blocks B, B bus drives B and C (yes B can self-target). Now there is a conflict: B would be blocked, but at the same time if Bs action is successful, they are no longer targeted by the blocking. So here we need to know: What happens first? And if Bus Driving happens first, then it is executed and results in C being blocked.
Now, if killing was also roleblocking, then in a situation where A kills B, B doctors C, we would have to conclude that Bs action fails. But that is not how I would want to resolve things.