When I started here the same account was used for all servers and services. All new servers get new accounts created though and we're working on changing the account on old servers. We do use the same account for all services on a box.

The only reason it's a pain to do it this way is the IS Security team is so far behind that it can take a couple weeks to get a new service account created. But it's worth it knowing that if one account gets compromised or locked out that it's not going to affect over 150 servers in our hospital system.