I mean, I'm sure there are still plenty of people who have the whole dudes go to a strip club ladies go out drinking thing, with the veils and the penis cups and all that. I've always hated that thing. It just seemed so unfair--I've always been friends with as many boys as girls, if not more. Why don't I get to go to the strip club? In that model, are the female friends of the groom supposed to go out drinking with his fiancee and her friends? That seems stupid. But so anyway, I'm glad that model is dying.
I think probably what's killed it as much as anything, at least among the folks I know, is trying to figure out what do with a same sex couple. If two guys are getting married, you can't exactly go out with the guys, right? So all my friends who've married people of their gender have done it where both guys/ladies go out with their friends, without the partner or his/her friends, and just has an awesome time. And the straight people got jealous of how much less stupid that was, and copied it.
So now it seems like the whole bachelor/bachelorette party is more of a "hey let's get together and have good old times like we used to when we were single" party, with the male and female pals of the bride or groom getting together and reminiscing and drinking beers and junk. Not that strips clubs can't be involved, obviously, but the whole "get your last view of other people before you commit" trope doesn't really work the same way. Most people I know who are getting married already live together and haven't slept with other people in years, but also are grown ups enough to know that ogling naked attractive people is fun for everyone, and not in any way cheating.
If you had asked me what I thought of bachelor/bachelorette parties before my friends started having them, I would've said that I thought they were idiotic and anti-feminist and needed to go. They always seemed to me to be based on the idea that women are nagging harpies who suck the joy out of your life. That whole "ball and chain" idea that marriage means you're never allowed to do anything fun ever again. Which is really insulting--why would you marry someone who wouldn't let you go out with your friends?
Especially nowadays when people aren't waiting to have sex till after a priest okays it, and are going to wait a couple years before having kids (if they have them at all.) The change isn't really that drastic, it seems like, from living together to being married, at least in a day-to-day scheduling kind of way.
But now that I've attended some of these new-style parties, I can appreciate that they do serve a kind of cool function. They can remind the person getting married that they have are all these friends who love them, who remember the funny stuff they did in college, and who think of them as them, not as half of something.
When you're in a serious relationship, married or not, it's easy to start feeling like a unit made up of two movable parts, and it's important to remind yourself that that isn't the case. I mean it is kind of, but it's nice to be reminded that you have a whole other you outside of the shared world. Instead of having that funereal air of "this is the last time you'll ever fill in the blank again," the thrust is celebrating what a great cool awesome person your friend is, how kickass it is that they found someone they love enough to get married to, and how we'll all still be friends together after the wedding.
I hope this doesn't sound too cheesy, but it's a way of commemorating a big change in someone's life as an individual, before they do it as a couple. Friends are like a little homemade family, and we remember and document each others' lives. The modern bachelor party reassures the groom that his friends are on his side, if he ever needs backup, or even if not. That we love him no matter what happens. It's also a great excuse to get drunk in the afternoon and go waterskiing. But who needs an excuse for that?