What's funny is he makes these general statements about what's "obviously" true that really wouldn't be problematic if he said them as his subjective preferences.

To me, working out is really about as much psychological as it is physical in that I won't make the same physical effort under one set of conditions as I will another just because of my level of enjoyment and/or motivation, so I think it's perfectly ok to say "I find I can't make myself put the same max effort in on the flats as I do climbing." It's when he starts making the obviously false claims about how nobody else can that it goes back to his stupid "heavy bikes are better because you get a better workout" kind of reasoning.