I always like to carry my own set of tools to fix basic mechanical problems my the bike. Those who repeatedly come out without a pump, or tubes, or patch repair kit then expect others to lend them what they need. Arghhhhh.
I tend to assume (non-habitual leaving-the-toolkit-on-the-kitchen-table mistakes aside) they're the ones who also lack the skills to make the repair, but maybe I'm wrong and they're just lazy? Much as it irks me, I don't think everyone should need to be a bike mechanic, or have the strength required to operate a pump or fit a tyre in order to cycle. If someone's puncture repair technique is mobile phone and a taxi, then fine. Just don't take the piss.
What Kim said.
I carry on my bike in my top tube bag the tools needed to fix every part of my bike that i might need to at the side of the road, except for a bottom bracket tool. I willing share this tool kit with those I ride with, where possible I try to teach people how to fix their bikes if they don't know.
I don't think having to be a bike mechanic should be a requirement to cycle. And round these parts there are companies that do for bikes what aa/rac/anwb do for cars, reducing the need further.
But I do think people should start the ride on a mechanically sound bike, even if it was made so by their LBS, rather than themselves.
J