Thanks to all.
I'm in Canada and here we have what's called "co-authority" with the dispatcher. This exists until take off basically. Then it's PIC solely. In all the years I've been doing this (many!) I have only had resistance to a request for more fuel once. I made it clear that the flight would not depart if I didn't get the fuel and that was that. It works pretty well.
But I also sit in the back of these things and I'm guessing that new Captains are fairly well indoctrinated into the new emphasis (obsession) with carrying min fuel. We all become old farts eventually but the message I get is that my 35 years at this is mere silliness when compared with the new thinking and "rational risk analysis etc etc". I will keep doing what I've always done. Any new Captains out there with a POV?