being a "great musician," in terms of knowing your instrument or gear inside and out, does not make you a good composer.

having more limited knowledge of these doesn't make you a bad one either. if that was the case, no one would speak of punk or early house/techno in the reverent terms they do.

that said, techno is kind of past the "presets on a 303+presets on a 909+simple patters" period, and hasn't yet entered a period of anti-technical lowfi production (though believe me, it's almost assured). right now, you need to demonstrate a certain level of technical proficiency behind the boards (real or virtual) to get noticed.

being able to play a non-electronic instrument, or not, doesn't seem to have much bearing on whether someone makes good techno at all.