@RosaWaiting
There are definitely people who see a funeral as an outing.
Victoria Coren’s story pretty much sums up how I see those.
We were lucky with dad’s funeral, all of us just wanted to get it done, so there were no announcements and no hangers on. We also felt if people hadn’t been in touch recently, there was no need for them to come and gawp at one of the worst days of our lives.
@TabbyMumz
I've never been to a funeral, thank god. I tend to think you should only go if you know the person. I can understand partners of close family going though, to support their partner. We didn't go to a very close family members funeral for various reasons, but were surprised to hear people went who only met the deceased once, for half an hour and even muscled their way in to the family funeral cars. They said things like "we loved her you know"....when they'd only met her for half an hour and the deceased didn't like them very much.
YES YES to these 2 exactly. People going to funerals of people they didn't know (or barely knew,) and funerals of people they've had nothing to do with, for say, 15 or more years is just WEIRD.. Also makes you look a bit needy, and rather attention-seeking. Unless you are going to support a friend or family member who knew the deceased, then why on earth are you there? 
Couldn't be arsed with them when they were alive, but show your face now they're dead? 
As I said, if you've had sod-all to do with me and my nearest and dearest for the last 10-15 years or more, you are not welcome at a family funeral. A few people have said something about teachers they knew. OK, I can understand you'd want to attend the funeral of a teacher, if you (or your child) had been to school and had that teacher for lessons within the last 10 years; but if you finished school 20 (or more) years ago, it's bizarre to want to go (IMO.)
As I said, It smacks of attention-seeking, and is quite ghoulish.
@jennymanara
We have a branch of our family by marriage who are very insular. When their GF died only very immediate family went, about 5 people. They were clear it was invite only. That felt very strange to me, but did reflect the very insular approach to life they have.
And so WHAT if they are insular? That's their choice, their business, and their right. Does my head in when people think they have a right to tell others how to live. 
Also, I'd rather have ONLY 5 to 10 people at my funeral who love me and care about me and are there for me all the time, and in my life when I need them, than 150 people who have had fuck-all to do with me since the 1990s, or early noughties, and/or are just there to show their face. Nope. They can fuck off.
Me AND DH are having funerals that are strictly private, and only the people closest to us (who show they care while we are alive) will get to come. The folk who have had fuck-all to do with us for the past 10-15 years or more can piss off.
Didn't bother with us when we were alive??? Then don't bother coming to show you 'care' when we're dead. As I said, if DH dies first, and someone (who has not been arsed for more than a decade,) discovers where and when the funeral is, and turns up at DH's funeral, they WILL be told to FUCK OFF! And he will do the same if I die first. They will be sorry they came, I can promise that.
And I really REALLY don't give a shit what people think about my views and opinions.
@Pinkblanket
Personally I'd rather not go to any funerals at all ever. I would say it is quite common for people to go to support those who are still living, even if they didn't know the deceased well. I also have a friend who despairs of her elderly relatives going to every funeral they can find, treating it as a jolly, and even taking their Tupperware to the buffet. So, I guess there is a wide spectrum!
Yep, I know a few people like this. Sounds like there are a few on this thread.
Serial-funeral-attendees. 