There's nothing particularly experimental in playing Bach on piano, and Bach was never experimental to begin with. He knew perfectly well what he wanted to achieve, and his music should be played as naturally and as perfectly as possible, regardless of the instrument used.
Exactly how would you define experimental, or does the word have no meaning?
Even though this doesn't necessarily follow as an argument from what you said, I'll remind you that playing can be natural and perfect and still take risks and be experimental, e.g. Pogorelich in practically everything. Obviously, you know this because you find Perahia and Hewitt bland. I'm also a big fan of Gilbert's English Suites, incidentally.
Nothing experimental about performing music with an instrument on which it was not written? It's almost experimental by definition to use a pianoforte, to make a decision about precise and sensitive dynamics in place of those texturally realized or implied--unless you think there is no difference between a Steinway and a clavichord. Just because we're so used to hearing a piano doesn't make it not an experimental activity, at least with a smart pianist.
In any case,
Bach never experimental? Hello! Art of Fugue, or listen to his organ music after listening to Buxtehude, or his exploration and synthesis of concerto styles. And experiments build on other experiments by others, e.g. The Well-tempered Clavier's exploration of keys and possibly temperament.
I suppose you know that he knew what he wanted to achieve, after having a séance with him? As a young composer he had no doubts, struggles, or preoccupations, just like all geniuses, right...
