Playstation Network players' gaming tags are shown, but only to other PSN users. However, this is not a thing for PC or Steam. PSN also does not have any way to really moderate what requests or messages come your way unless you block any and all interaction from the outside, as far as I know. I believe someone can still add you to a group and message you.

PC players cannot see PSN tags, so why is it even a feature. Steam accounts would also have an account specific tag, and yet it is not shown.

This is unsafe, and to an extent prevents some people from being hidden away on an alt. A player could want a fresh start, try out a character model, or avoid harassment. But if they are PSN- oops everyone knows.

I suggest that the system should be all alternate tags/naming or none at all.