i can play the piano... so i guess i'm a musician too... ?!
every sound other than vocal's on outkast's "aquemini" album was made with a sythesizer. if you've ever heard the entire album, i would think it would be clear that there is a difference between simply using a synthesizer/drum machine/sampler to produce sound and using a synthesizer/drum machine/sampler to produce music.
roger & zapp in the late 70s/early 80s used primarily synthesizers for their music.
michael jackson's "off the wall" album and "thriller" albums (both produced by quincy jones) featured a synthesizer all over the album.
simply pressing a button and duplicating a sound isn't all that it takes to make music, whether it's rap, funk, r & b, or any other genre. if that's the case, then plucking strings on a guitar or just picking up a set of drum sticks and banging on drums would be considered making music. i think the both of us would agree that either of those cases would not be making music, it would just be making a ruckus.
if one doesn't know rhythm, tempo, cadence, etc. one won't be making music with a drum machine/sampler/synthesizer.