I dont know about not understanding 'if you never tried'. With very few exceptions, I think most people started riding on a single speed. For me, its about the simplicity of a minimal machine. Reminds me of being 4 on my banana-seat, coasterbrake bike.

Oh, and close to zero maintenance in over 10 years on my one-and-only, used for everthing from races to touring to trailriding, beat-up-old clunker which will blow the doors of plastic-clad gearhead-mounted vunderbikes doesnt hurt, either.