let me get this straight...you saw bert jansch on bbc, then you heard a doc watson record. this convinced you that having a pickup on an acoustic guitar "compromises" the sound and that anyone who buys an acoustic guitar for the sound is "living a lie" if they use a pickup?
have you ever even played a gig? there are soooo many factors that contribute to the sound you hear as an audience member at a concert, and even more in the studio. i've played the same pickup through the same board with the same speakers in different rooms with entirely different results. in one room i, i sound like elvis. in the next i sound like an old bootleg recorded in a basement. i've used microphones and 3 or four different types of pickups with direct boxes, tube pre-amps, etc.