One of the best reasons in the world for avoiding the entire genre: leave it all to family and friends who will never have to carry the responsibility nor the balme for anything. Who ever looks at old wedding pictures anymore? About the worst thing I see in some otherwise beautiful homes are those silver photo-frames filled with stilted images of black/white fashion modelled by nearest and dearests! Fill'em with happy snaps, by all means, but let them be real pictures, not just another form of passport photograph.
Should anyone think that feeling redolent of cynicism or bitterness, think again: marriage was the single best thing that ever happened to me in my entire life. It's not marriage, it's the bullshit built around the event that sours.
Actually a wedding is a fantastic time for photographing people. At quiet times during the day it is possible to get wonderful character shots of guests and their families who otherwise would probably never be photographed in this way. Most peoples' experience are static shots in a studio and not well crafted available light pictures. And of course some people look at their wedding pictures over and again. I regularly speak to couples who tell me they still cherish the pictures I took of them ten years ago or more. Yes, the wedding industry is a monstrous behemoth and quite often tasteless. But let's face it, most couples will want some pictures of them on the day and it is down to them to choose a photographer who will produce the sort of pictures they want.
Regarding the kiss - it is true that sometimes the kiss will be incredibly fleeting - but you are right, the well prepared photographer should not miss it.