The MD got cannibalized by Sega's own fracturing of their brand. With a half dozen models of Genesis/Mega Drives in addition to 2 different expansions that played different games and third party spin offs of the main models, not to mention various models of the Nomad, consumers eventually became overwhelmed by choice/monetary investment necessary just to play the latest Sonic game. I don't know anything about a "bad rep," but it died because Sega had no idea how to run a sustainable hardware business.