I remember well the discussions of pigments and brushes in art school in the 70s; I'm sure Alain heard much the same in his Beaux-Arts days. And of course they exist today. But such discussions were (and are) miniscule compared to the enormous amount of verbiage, passion and angst spent in discussions (online, printed and otherwise) on the technical aspects of camera gear since digital came to the fore. Alain's comparison is quite correct: the competitive yardsticking, emotional self-identification and brand awareness that are common in gear discussions among photographers are rare with painters.
There are legitimate and understandable reasons why more verbiage, passion and angst, as you put it, are spent in discussing the technical aspects of camera gear.
First, there is probably a far greater number of people who use cameras than there are people who paint, so such discussions about camera gear will
appear to be greater.
Secondly, a camera is the one essential tool required to take a photograph. One doesn't event need a paint brush to paint. One can throw paint at a wall.
Thirdly, a camera, on average, is a much more expensive item than any tool used for painting. When people are considering spending their hard-earned cash on expensive equipment, sometimes as much as $100,000 or more for MF equipment with lenses, it is perfectly natural and understandable they would want to thoroughly investigate and discuss the merits and advantages of such expensive gear.
Fourthly, the computer monitor, with appropriate software, allows the photographer to clearly see any defects and unwanted noise in his images. I'm quite sure if any painter were to apply dark shades of paint which, on drying, were to exhibit noticeable streaks and unintended patterns, he would exhibit a great deal of angst.