Ugg. I've seen that system used at other places and it's miserable. Devs had accounts but users and interns used a shared account. You get a vague ticket opened and they forgot to add their name. Also, would updates get blasted to everyone at the company? I'm pretty sure our's just turned them off for that account. So they don't get pinged when the ticket is resolved or needs feedback.
This is confusing to users. Seeing who made changes and who opened issues is really important. Having all users share an account would be confusing to see the same person asking and answering questions.
Also, making a thousand users learn a new userid and password is a support nightmare.
I understand that this type of usage would only be suitable for small teams.