At the time it was on, I thought Friends was a great show. Most people did. I remember bars such as Scoreboards running ads in the Collegian along the lines of "Come watch Friends with your friends" and then adverstising their drink special that night. It was a big deal among most college students. And yes Jennifer Aniston had a lot to do with it. Now, whenever the reruns come on I can't watch them. Their pretty terrible.
So to answer your question it may have just been the in thing to do/watch at the time.