This assumption is off. I have barcon indexed shifters on my Tandem. I have had indexed shifters on other bicycles also. The brifters just don't interest me. I have hydraulic rim brakes on my Tandem. So brifters are not available for what equipment I use on derailleur bicycles. My touring bicycle has a Rohloff on it. There is a way to use brifters with the Rohloff but you can't shift more than one or two gears at a time with it. I know some people are uncomfortable shifting with any shifter that requires them to move their hands away from the brake levers. Manufactures have made it so only their exact platform will work. The friction shifters will work on most anybodies derailers.