Don't wait until after your CFI ride to earn your tailwheel endorsement. It'll make you a better stick and rudder pilot today.
Sure everybody coming up the ranks today and finger f$@% their way around a G1000, but can they perform a smooth three-point or a wheel landing in a crosswind?
Besides, who's going to fly all those Cubs, Pitts, P-51's, and T-6's if no one flies tailwheel anymore?