At least I and thousands of others had many outstanding experiences there in the 1960's and 70's. Time moves on, and Central and Davis now carry the mantle.
Harvard Square itself has morphed into something corporate and dull, a sign of the times nationwide.
As I've noted upthread, I couldn't disagree more--there's still so much that's unique and captivating about Harvard Sq. in terms of restaurants/nightlife/general ambiance and I don't think it's lost a thread of "authenticity," however one wishes to define it.
As for "outstanding experiences of the 1960s and 70s": my mother was at school there from 1964-68. You know what she likes to talk about when she remembers the scene from back then? Just how much misplaced nostalgia there is for that time. According to her, all of those fabled diners were shabby and the whole scene was rather dingy. (Mind you, she was coming from LA, where so much of the built environment had just been built...). She's not a curmudgeon and I'm quite sure she had a great time in school there--just being a realist. And, I hardly think she's alone among Baby Boomers in thinking there's way too much sentimentality attached to the Harvard Sq. of that time.