Non-privileged user visibility of other users processes

It always seemed very weird to me that in Linux (RHEL 7 for example) by default it is possible to see any process detail of any user on the system. It seems it can be be enabled as an option on the /proc directory mounting.

Depending on the architecture, this can be a security issue, and it seems to me there is little awareness on this. Or, nobody seems to care.

Alternatively, the default could be that it is not possible for any account (but root) to do that, and technically it could even be an option to have that disabled at all. Want to see the processes of a user ? Become that user, or be root.