Tour riders are EXTREMELY conservative, well they were back when Lemond pushed clipless pedals, more helmets, and aerobars.
The nameless scapegoat who was totally the only person using EPO pushed more thorough full-system wind tunnel testing/aerodynamics and a lot more scientific testing, and even (gasp) clincher tires.
Euro riders for a long time worshipped Eddy Merckx (who was totally clean and never doped) and thought you basically only needed an italian bike and nothing else and were culturally averse to change.
Also, keep in mind the Tour riders are basically showcasing industry products, and those products aren't really that diverse in their sourcing, especially with globalization. They all run on whatever they are getting for free or at a vast discount from the two or three providers in each equipment category.
The nameless scapegoat who was totally the only person using EPO pushed more thorough full-system wind tunnel testing/aerodynamics and a lot more scientific testing, and even (gasp) clincher tires.
Euro riders for a long time worshipped Eddy Merckx (who was totally clean and never doped) and thought you basically only needed an italian bike and nothing else and were culturally averse to change.
Also, keep in mind the Tour riders are basically showcasing industry products, and those products aren't really that diverse in their sourcing, especially with globalization. They all run on whatever they are getting for free or at a vast discount from the two or three providers in each equipment category.