“Train what you want to be good at” 
I mean, it doesn´t really come as a suprise that in order to improve your TT performance, it´s more efficient doing “longer steady state” VO2max intervals, wheras Tabatas are more beneficial for crits, road races, CX, XC etc where you need that repetability! That´s maybe a reason why you don´t see the GT contenders doing a lot of Tabatas 