I assume that the gist of the argument that a taildragger makes you a better pilot is that it is more demanding to taxi, take off, and land. I suppose if you are the sort of person who does as little as possible to successfully fly, that would be true. I would also suppose if you are that sort of person that you should find something else to do with your time, that flying is not for you. We should all be trying to refine and improve our technique all the time. I just don't see the advantage in flying an airplane that's ready to bite you should you make a mistake or should an unexpected gust occur, unless that airplane provides you with something you need in return. I see why someone who operates off of a soft field would want a Cessna 180 instead of a 182, but for those of us who only fly off of hard surfaces, I'm not seeing it.