The real reason is because we tune instruments differently. Anything about "why would you want to be a copy cat of Bach?" is just non-sense - musicians have be

The real reason is because we tune instruments differently. Anything about "why would you want to be a copy cat of Bach?" is just non-sense - musicians have been copy-catting each other endlessly since music existed, and still do today. The writing technique of the baroque era revolved around line conductions that dodged harsh-sounding intervals in the temperament of the time. Nowadays, we tune using equal temperament. Equal temperament doesn't have harsh-sounding intervals (except flat 9th on a major chord), which makes classical writing technique obsolete.