This was the timeframe where more and more manual work was automated. Hence it was a common situation where input used to be given by a human, but now comes from another application. The simplest way to do that kind of retrofit was to drive the UI from the application: The application fills in its own gui fields which triggers the validation, then simulates a click on OK.
This caused al kinds of ungodly messes. You need a gui for background processes, reliability was low, etc.. 3 tier architecture were a way to say 'never again' to this style of programming. Forcing people in to it was necessary.
But that was another time. Mindlessly applying an architecture without understanding why is of course dumb. But not applying an architecture without understanding it's pros and contras is just as dumb. It all depends on the quality of the architects in question.
Not that I want to call you dumb, of course. IT today is different from 20 years ago.
