Possibly. But don't forget how unpleasant a lot of socialising can be. Beneath the smiles and hugs there is a lot of jealousy and resentment bubbling away. Many people struggle with self-esteem. And being around obnoxious show offs, or people who've achieved more than they have, is torture. Maybe it's just me, but I often sense this discomfort and fear when I meet people for the first time. You can feel them weighing you up and thinking "are you a threat to my self-esteem? Are you going to make me feel crap about myself?" etc.
Being with people you really like is wonderful, and I agree that we should make more effort to meet up with good friends. But I can't imagine anything worse than a barbeque with random strangers. I really hate this idea that we're obliged to be friends with people just because they happen to live nearby. I was a kid in the 80s, and have no happy memories of my neighbours at all. The guy next door was an absolute prat – one of those unbearable idiots who think they're funny when they're not. He was also pompous and aggressive. Next door to him was an odious, arrogant solicitor. His wife was lovely, but she adored him, laughed at his jokes, and hung on his every word. Ugghh, it was awful to watch. I was friends with their kids, so we were sort of in and out of each other's houses, but it really wasn't the idyllic childhood you're painting.
If people socialise less, it may be because they've got better things to do! Video games, DVD boxsets, Ipods, etc, are more entertaining and less stressful. I've known very few people who are as interesting or entertaining as my favourite books. Thanks to the internet, we can now order any book we like from anywhere in the world. We can also order any album or DVD. I think what's happened is that the introverts (who make up a pretty large chunk of the population) no longer feel the need to socialise. They have more than enough to entertain them.
I know I'll get flamed for this, and I know someone will say "huh, well you sound like a barrel or laughs," or "well maybe no one likes you either either," but I honestly can't be bothered with most people. The majority just aren't worth the effort. A minority (maybe a quarter) are horrible and repellent, and another big chunk, who are nice enough, are boring. I'd rather be reading or listening to music.