Pieman0920
Smash Master
I was aware that it probably came off like that when writing it, but I couldn't really think of any other way to put it. As it stands, Ridley not only has the fan demand, but also more series importance than any other Metroid character by far. (Bar Samus of course) As KumaOso said right above me, Metroid's cast is so small (due to Samus killing every single supporting character...) that this fact alone is probably why Ridley is the only valid canidate, with the possible exception of Adam, though that's up in the air for right now.I am sorry but this really sounds like "If Ridley cannot be playable, then no other Metroid character will!" which basically is akin to "If I cannot have him/her, then no one else will!"
I think we all know deep down why ZSS was added...I don't think Zero Suit Samus was added to make up for no playable Ridley. She was added long before Brawl was even announced and most certainly long before there was even a fan demand for Ridley. Ridley and Meta Ridley were likely added as bosses to make up for no playable Ridley. It certainly would explain why Sakurai changed Ridley from an intended Assist Trophy into two bosses. Sakurai knows the Ridley fans want Ridley but he also knows that its very hard to make Ridley a practical and viable Smash fighter due to whatever reasons he might have. Maybe he felt that Ridley is better suited for boss fights than for Smash matches.
But anyways, given that Sakurai's statements indicated that Sonic was the only character who was added because of the polls, it is probable that Ridley's double boss status was a responce to his popularity, which was undoubtably high. Still, given that Sakurai has also stated that while difficult, that putting Ridley in is possible, I'd expect him to have very high chances for SSB4, especially as his role in the series will keep on going, as seen in the Other M trailer.