I agree with the fallen madonna. No-one has the right to dictate to another person their concept of what a wedding should be. If you like kids at weddings, then have children at your wedding, and if you don't then don't but no-one has got the right to dictate to other people that they should / should not have children at theirs!
I personally wouldn't have children at weddings myself, all too often I find them boring, so I think that the concept of making a small child sit around, bored out of their brain, being well behaved with not much to do all day completely inappropriate. And I know on the few occassions I've had to bring my daughter with me, it has always been a stressfull occasion, as she has just not got the ability to sit quietly for the hour long service, the hour and a half sit down meal whatever (no matter how many toys I take along!). Kids end up running around, messing about and imo spoiling the day for everyone else. Maybe I'm being a misery guts here, but even I get annoyed by other people's kids who mess around at weddings!
Final point, again someone else iterated it, but why do you expect that all invites have to include the whole family? When my eldest daughter gets a birthday invite, do I expect her sibling to be automatically invited too? No, because they are individuals and it is my eldest daughter who is the friend, not the youngest. Likewise, if I am invited to a wedding, should I expect my children to be invited too? No, not automatically (although it is nice if they are!) because often the bride is my friend, she is not friends with my children! We can accept the concept that we are individuals and so get invited individually to things, therefore it is perfectly acceptable for us adults to get invited to things without the kids... geez, some people will be demanding that their kids get invited to the hen party next!
So bringing me back to my original point... people can have whatever kind of wedding they like - if you like kids at weddings, then have them at your wedding, but this does not give anyone the right to say what other people should do at their weddings. If you don't like it, don't go but that doesn't give you grounds to moan or bitch about it. Just get over it.