This was a good situation for the most part. The majority of the system administration could be handled centrally in the air-conditioned computer room and users got good support, regardless of whether they were next to the computer room or across the country. Very little information had to travel to the individual desktops because of the central processing. Now, PC's have started to impact computing. Every user has a mini mainframe on their lap or desktop.
All processing is done locally.
If they have a network in place, all of their files are stored there, but to give them the speed they keep asking for the programs must reside on their local machine. The users don't want both a PC and a dumb terminal on their desktop. At some point, they might like to sign a form or mark up a document. Two monitors just won't do. The PC market has become huge and mainframes are becoming dinosaurs in all but banks and Fortune 500's.