As for the common 'they snag on vegetation' argument, I really don't get this. They don't make the bar any wider
I've had a couple of falls as a result of them getting snagged on brambles and the like. I don't know whether or not a non-bar ended bike would have fared better in the same circumstances but I haven't had the same style of crash on the bike without them.
I still use them for all the reasons given above and, as a few have mentioned, spend more time on them than the grips. Well, sort of palm on bar plug/fingers on bar end kinda style, if you get my drift.