I guess the debate is one between authenticity (playing period music on period instruments) or adapting period music to modern instruments. Many people don't know it, but it's a fact that Bach played the piano. It was invented toward the end of his lifetime, and he got to try out the earliest, unperfected pianos--but still preferred the harpsichord. However, if Bach could return to us today and sit at a Steinway D or a Baldwin SD10, he'd be blown away by power, capabilities, and potential that he never even dreamed possible. (Liszt would marvel at it, of course, because he always wanted the latest and greatest in piano technology and development.) Likewise, I have no doubt that Bach would adapt immediately to the modern instrument and all its possibilities. He'd love playing a Partita on a Steinway--and it would be interesting to see what he would do with the pedal once he became accustomed to it!
While it might be interesting to me to hear a Schubert or Beethoven sonata played once or twice on a fortepiano as a historical curiosity, had I not suffered through that too many times already, I far prefer to hear those and other Baroque and Viennese Classical composers' works performed on the modern piano which does more justice to their soaring visions.
I started playing piano when I was 8. My first instrument was a Chickering "square grand" from the 1800s with the smaller keyboard radius, the tinny tone, the fear of breaking a hammer when playing a bass chord, etc. The tuner almost had a nervous breakdown trying to service it. When he quit, I had to tune it with a roller skate key. (Inline skates hadn't been invented yet--you locked the roller skate onto the sole of your shoe using a key.) I was never so overjoyed as when I got my first real piano. Playing that old Chickering was enough exposure to period pianos to last me a lifetime!