It may be tempting to answer this question by plugging your idea of the greatest modern artist, or perhaps the most loved artists of this day but to be accurate to the history of Bach, I'd say that the modern day Bach would have these features-
*They are not popular or mainstream; Bach wasn't in his day.
*They reject the current trends for a more old fashioned style but hone it to perfection and merge it with complex techniques of the even more distant past to create something truly unique.
*Their music is exceedingly complex, imaginative, and innovative.
Based on these criteria, who could it be? The answer eludes me personally but maybe one of you have an idea.