Steam is dumb and annoying - especially Steam Support

Why aren't login details stored per user profile?

Not being able to run more than one copy of Steam at a time on a computer, I accept.  Even though you could check and make sure the system is only capable of a single session, or you could check and make sure only one copy of steam is functioning.....    but still, if you have decided that's how it is, then I'll have to accept.

But, how come login details are not stored by user profile?  Why does my son's account log in when I start using the computer?  Why does mine login when he's using?  That's just retarded.  Is there any way to change this?

It's almost as retarded as making people create a separate support account.  Yet I didn't have to enter all my details, because they just looked up my Steam account.  Dumb and annoying!

Yet..... When I go to hit submit on a ticket, I have to enter my Steam Account Login name.  But I entered that when I created my separate support account.  They used it to send me the confirmation email.  They know my steam account is linked to this support account.  Why do I have to enter it again?  Dumb, annoying and retarded!