I am quite a fan of Bach, Mostly for the keyboard but I have sampled many of his other kinds of works (One should say sampled when talking about such a huge output) and pretty much always enjoyed it and found the standard to be very high.
Though I don't believe in the near cult-like status he has achieved which I feel is actually harmful to him and music in general. I also think his writing ability was limited in the fact he did not write with dynamics in mind which to me is a crucial element of music.
To me the most important question regarding his music is not "How would Bach have wished it in his own time?" As many people seem to think but rather:
"How should we play Bach IN THE PRESENT?"
The shift of focus to this question could indeed see Bach find a wider audience rather than catering to the inbred elitist one he now has. (Not to insult ALL Bach fans but you must know what I am getting at here...)
Indeed, except for the case Glenn Gould, you could indeed rather say 'sampled'. And I agree, to a certain extent with you. However, I think it is a combination of both what Bach wished his music to sound and how we should play Bach nowadays.
A lot of people always say that they don't like the idea that all of Bach's keyboard music is nowadays mostly played on an instrument for which is was not in fact written. I'm not inclined to apologize for the fact that I indeed do play Bach on the piano. I really think that the piano does offer a great many resources which are entirely appropriately applicable to the music of Bach, and that it offers some which are very inapropriate. So it really becomes a question, imo, of adapting/using those things which really work within the perimeters of the music.
There are, of course, two very contrasting arguments, one of which is that if Bach would have known the piano, he would have certainly used the piano. And I'm sury he indeed would have used it, I mean, he was a very practical man in the most ways we know. In fact, a few years before he died, he saw a 'Silbermann' piano, and he had some good things to say about it.
However, the other argument is that Bach didn't know the piano as we know it today, and he didn't think in terms of it's capabilities, and here I think is were most people go wrong. Because if one believes that argument, one also believes that Bach cared very deeply about the specific sonorities he used when writing his music. Almost as if he was a slave from the instrument that he wrote for, and I just don't think this is true. There ar just far too many examples that proof the contrary.
For example. The Violin Concerto in E Major, a wonderfully strong beginning. But it works fine too for the keyboard in D Major. And the other movements of that concerto also turned up in the cantatas, where they're even accompanied by voice and the also turned up on the organ.
So, in short: I don't think if Bach would have known the piano he would have turned himself into an 18th-century Alexander Scriabin. But that's just my opinion.
I also don't think Bach's keyboard music needs to much dynamics, and certainly not those written in editions like Schirmer or Peters. I rather use Henle and already have all of Bach's keyboard music piled up on the Henle side of my music books closet.