Thanks to M.Ted for invoking the name of Stanley Jordan, the true master of this rather limited technique.

From what I saw of Eric Roche ~ the "Bushwhacking" video, I think the first YouTube link referenced in this thread ~ there was little or no "tapping" involved at all, just some impressive and very percussive right-hand technique that blurred the line betewen "picking" and "strumming," along with some fairly repetitive melodic/harmonic patterns of the type usually associated with open tunings. I did enjoy the selection, but if pressed I'd have to make the distinction that I enjoyed the performance a lot more than the music.

Some of this stuff I like well enough, other selections leave me cold. One of the aspects I do NOT particularly enjoy is how a given piece is often not a song or melody that stands on its own merits, but a gimmick designed specifically to act as a showpiece for a bit of technique ~ usually something built around the quirks and easy harmonies/dissonances built into some non-standard tuning.

Of course, the same could be said about whole categories of "new folk" and even truly traditional folk music, like, say, "Spanish Fandango." I doubt that anyone here would dare criticize "Spanish Fandango," or whatever that song was about "Vastapol (Sebastapol)," two tunes after which their characteristic tunings were named.

Most of these "tapping" showpieces are fairly simple compositions and seem to be played in open tunings. Stanley Jordan's work is quite different in that he plays in standard, and frets with one hand while tapping with the other. That is, he does not restrict his tapping to open strings ~ something that may only be possible pon the electric guitar, because there is probablby no way to generate enough volume to be heard when tapping a fretted string on an acoustic instrument.