Mumsnet is hyper-conservative when it comes to weddings 
in other words, people disagree with me and I can't accept the concept 
MN is not ONE entity, it's made of posters of different gender, background, age, countries even. Disagree as much as you like, it gives you a good feel of what people think. There are very few rules for a wedding guest, it's astonishing how it's still too much for SOME. It's not about you that day.