> The user can install his/her own kernel, in that case it makes sense to make these files readable only for root.
In bigger data centres this will most likely be a no-go. The reason is that these environments heavily depend on automated update routines. If you need to recompile the kernel to ensure the address space is unpredictable, that will just add more maintenance complexity and also add another possible place where things can go wrong. Which again will make most sys-admins ignore this threat.
In addition, with commercial Linux distros it might even make it more difficult to use of their support services. As they most likely won't support "home brewed" software packages, even if it's based on their sources.