Shamus hates the 70s, and he seems to have pretty good reasons. Politically, the 70s were pure shit -- we're talking about a decade that saw three US Presidents, two of whom were Nixon and Carter. (Now, I like Jimmy Carter, but I like lots of people who would be crappy Presidents.)
I'm not sure I'd dismiss a lot of the cultural stuff of the 70s, though; there was quite a lot of good stuff. This is a tricky point to make. Shamus notes that Star Wars came out in 1977, but George Lucas was very clear at the time (and ever since) that he made a feel-good space opera out of a reaction against the tenor of the 70s. The same can also probably be said of his other great film from that era, American Graffiti. Ditto Grease, a movie whose heart is most certainly not in the 1970s.
Maybe some of the bleaker films of that era aren't to Shamus's liking, but I can't declare a decade a washout if it produced films like Chinatown, Saturday Night Fever, The French Connection, The Exorcist, and (by their reputation, since I haven't seen them in their entirety) the first two Godfather movies. Also, the 1970s saw the arrival of Steven Spielberg, with the greats Jaws and Close Encounters of the Third Kind.
Here's a site on the film history of the 70s. A lot of great, although mostly admittedly bleak and cynical, films came out in that decade.
I'm likewise unwilling to cast out all of the television of the 70s. Sure, lots of it was crap, but lots of TV is always crap. There were also Barney Miller, MASH, The Bob Newhart Show, The Muppet Show, and some other stuff that tends to be highly regarded. Saturday Night Live started, although it's worth asking just how funny it was.
Music? Well, all that big-haired heavy metal from the 80s had its roots in the 70s, right? Jerry Goldsmith was at the height of his powers at the beginning of the decade, and at the end of it, John Williams was reaching the height of his. Disco was mind-numbingly awful, for the most part. (I have a weakness for the Donna Summer song "Last Dance".)
I don't really remember the 70s all that well from a personal standpoint, so this post isn't meant so much as a defense of the entire decade as a defense of some things from that decade that I like, and not much "defense" at that, since again, lots of this is a matter of taste. I certainly don't deny that the fashions of the era were mostly ugly (excepting that certain articles of workwear were popular at the time!), and that the cars were awful (just try watching the high speed chases of the James Bond movies of the period). We saw a Chevy from the 1970s in a parking lot recently, which by happenstance was parked next to a lovingly restored car from the 1950s. Talk about your "Beauty and the Beast" moments.
So what's my point? I don't know, really. Just that the 70s didn't completely suck, I guess.
(And I'm glad that on the "hippie" scale, I fall on the smiling, happy side!)