Why oh why are drop bar 29ers sized with stupid short seat tubes and stupid long head tubes?
Not sure which ones you’re looking at but that’s not particularly my impression. However, “longer” head tubes are (AFAIK) a result of the hooks wanting to be at the same general height as grips would be on regular bars but without having to resort to big spacer stacks and/or high rise stems.
I thought everyone liked a nice short seattube and, normally, the consequently greater standover / lower toptube.
But then again I’m not quite seeing them as you seem to be. Hey ho. It’s all bikes and buggering around in the woods 😎