There is NO comparison between Swift and any others you have mentioned above.
Yes, she has written songs, and plays guitar (a Taylor, no less...) - good for her. So does Michelle Branch, who came out firing hot with her song "Everywhere" when she was 18 (a MUCH better song than ANYTHING TS has done)...anyone heard from MB lately ???
Bottom line is, with Madonna, Jagger, Springsteen, Townshend, et, al that you mentioned above, they had SOMETHING DIFFERENT that people realized very quickly. They were revolutionary. They changed music and made their mark...TS is a product of a HUGE marketing push by desperate record company folks who are DYING to get their next pop tart out there. And the fact that she's being pushed as a country artist is such a big joke that even Shania Twain has to be laughing...
In 1964 many people thought The Beatles were a joke. I Want To Hold You Hand with it's cookie cutter lyrics. People thought a pop band's shelf live was 1 year 2 at best. Madonna was derided for many many years before people finally realized her talent. The early Who hits were not mega hits in America. They had to build their audience by touring, continuing to release albums and basically hanging in there. The first 2 Bruce Springsteen albums flopped. He was a bout to be dropped. Next Bob Dylan my ass is what most people said. Linda Ronstadt struggled for many years before Heart Like A Wheel came out and began her string of platinum albums. Neil Young's early solo albums were not huge hits. It was only when he joined Crosby Stills and Nash a supergroup that he began to have name recognition. I'm not saying Taylor Swift will be Madonna or Linda Ronstadt, but sometimes you never know. It takes years sometimes to evaluate an artist if they are able to maintain a career.