However, I also feel that that making non secret information world readable would have been the Unix way. This change made the life of a few script kiddies a very bit harder, but also made the life of many legal users significantly harder (in contrast with a script kiddy they have to maintain the fix in a more formalized way).
On Focal the correct command to (temporarily) fix the permission problem:
sudo dpkg-statoverride --update --add root root 0644 /boot/vmlinux- $(uname -r)
However, I also feel that that making non secret information world readable would have been the Unix way. This change made the life of a few script kiddies a very bit harder, but also made the life of many legal users significantly harder (in contrast with a script kiddy they have to maintain the fix in a more formalized way).