The main advantage of learning tail wheel first is that doing so mitigates the common problem of landing in a crab. Landing on the left side of the runway with the nose crabbed left is a problem with any side by side aircraft. To put the nose on the center line, the pilot in the left seat has to yaw the nose left. Students need to think, and instructors need to say, "put the center line between your legs." This problem is why you see more black tire marks on the left side of any runway.
Not that it has to happen nor that it should happen, but many who learn in nose wheel airplanes first land with the nose yawed left every time. There is little incentive to learn the correct longitudinal alignment as seldom does any damage result from this mistake. However, should they transition to tail wheel airplanes, this mistake will often result in a ground loop at enough speed to do serious damage.
Finally, anything we do repeatedly over considerable time will require many iterations of a different technique before the first becomes extinguished. It only takes one iteration of landing crooked to destroy an aircraft. Rather than tell high time pilots that they may have a problem, tail wheel training outfits usually only give dual. Also, tail wheel airplanes are seriously overpriced. Supply and demand. Not really that much better than the same airplane with a nose wheel, just low supply. And the hype, like i phones. You pay for that hype (demand.)
Download my free "https://tinyurl.com/Safe-Maneuvering" e-book.