IIRC, Captain Falcon was intended to be a big mascot of the NES, with Link and Samus. Pit was going to be one too, but that didn't wok out either. The MOTHER series is AMAZING, and my second favorite franchise after PKMN, but it had awful sales. MOTHER was translated, but never released until the VC version. It actually became the best selling eShop title for a while, until beat by MOTHER 2. MOTHER 2 did poorly at first because of a lack in advertising and a lack in interest of JRPGs at the time. As said before, it beat MOTHER and became the best selling eShop title. MOTHER 3 was never localized or translated, and is only playable in a fan translation, with no localization whatsoever.
tl;dr version: Falcon was intended to be popular, but that didn't work out. Ness' series did very poorly in sales, but were fantastic games. However, Ness became iconic through Smash Bros.