I guess it's a case of who u meet. I'd say u're unlucky to meet with a bad experience. I agree it's also a matter of different cultures & different working styles. I was lucky to meet with a nice main photog for my friends' wedding. It helped that they introed us to one another & that he was shooting film & me digital. For me I try to spot where the main photog is positioned & I look for an alternative view. & my way is to look out for any relatives or friends shooting & be mindful when I shoot (helped me quite a bit to avoid double flashes). The main photog was even generous enough to let everyone have a go at the family portraits. No problems with subjects attention there was enough common sense amongst everyone to make sure the order of cameras going off.
For me, I personally think weddings are kinda personal affairs, & actually many I know get friends to help them take photos for their weddings, of course limiting the number to 2 or at most 3. There will also be other ppl taking photos with their p&s, camera phones or whatever setup they have. But ultimately, as long as everyone is mindful of one another, I think everyone can shoot pretty happily. I feel an experienced official photog will know to understand the feelings of the relatives & friends & make provisions, or even arrange, for them to capture the joy too, because weddings isn't just a job assignment, it is also a sharing of the joy of a union.