It really doesn't sound like he has anything against messengers. I don't think anyone I work with would be offended by what he says. We might point out that we're fairly well conditioned by work, so I don't know what he means by physically untrained. Our work isn't the same as a structured training program and the nature of it does limit our ability to progress as cyclists(nine hours of start stop cycling isn't the best training for say, racing, I guess) but we are pretty much all in very good shape. Not professional athlete shape, but pretty good shape.
Not using the best gear available? We don't really need "the best gear". Any bike that you can average 25kmh on all day will probably do. It really just depends on what you can afford to keep on the road or what you personally feel like riding. Still we aren't running Di2, so I guess we aren't using the "best" gear. We're just running what gets the job done.
I know a guy who seriously rides a mountain bike with an integrated carbon fiber bar/stem, rigid carbon fiber forks and disc brakes. I don't know what the deal is with that but he's a strong rider and a better messenger than I am so I don't question it.