I agree with JoPie, and cannot see what the problem is.
Why can't people accept that not all events are suitable for all people? It does not mean that all children are excluded from all events, and certainly does not mean that children are excluded from society, or never get to go to restaurants - it's a fallacy to assume that (slippery slope argument!). Just sometimes it is not appropriate to invite children, just like sometimes it is not appropriate to invite older people...
Would you invite your Great Uncle Frank to a teenager's house party or a young person's first housewarming with friends?
Would you invite your granny to a 18th celebration with strippers galore?
Do you insist that your Great grandad attends your child's birthday party?
Or that you must attend all the birthday parties that your 6 year old gets invited to?
No, because in those scenarios it is not appropriate. It is not necessarily about excluding a section of society - but it is about deciding what is and is not appropriate on each individual occassion. Each situation needs to be determined individually and there is nothing wrong in sometimes deciding that an event is not appropriate for children or other people.
I happily take my children to some restaurants, and particularly frequent one at a local hotel where there is buffet service (no long wait between courses) and a play area for them to let off steam before and afterwards. However, I would not take them to a very posh restaurant where they would be expected to sit still and quietly for hours on end. They are too young to cope with that, and they would just end up ruining the meal for other people (which would be a very selfish attitude on my part, showing lack of concern for other guests).
If this meal is a chance for the families to sit down and talk about the wedding and have a long boozy lunch, then I would agree that it is not appropriate to take younger children with them. If we have family dos that are not appropriate for children, then I happily stay at home with them / get a babysitter - Its not fair on them (who just get bored) or everyone else (who then have to put up with their bored behaviour) or myself (who then gets stressed with them, trying to make them behave). Just why put yourself through it?
I wouldn't have a problem with it, because I don't see it as an issue of exclusion but rather I see it as an issue of what is appropriate for children to go along to. Some events are suitable for whole families (including children), some events are not. Some events are suitable specifically for children and teenagers (parties, concerts etc...) but are not appropriate for old people - different things are appropriate for different groups of people. There is nothing wrong in that, it's just life and I think we just need to accept that. Not including them sometimes is not the same as excluding them at all times. I think we need to keep a bit of perspective here.