EDITED: Fixed a major error after TempestTim
I'm not happy about clones, I never liked the concept, despite most clones being better than the originals. I loved how in Brawl, there were no true clones anymore (at most you had semi-clones, and that was debatable.) But clones are back in Smash 4 if the form of Dr. Mario, Dark Pit, and Lucina, all unlockables.
You're immediately thinking "EWW! THEY STOLE SLOTS FROM REAL CHARACTERS!!" The reality is, the roster was decided on BEFORE the game was even announced, and these 3 clones
(maybe Lucina was the exception
I forgot that Lucina was indeed a costume for Marth in original development but decided that "their minor differences" gave them enough reasons to make her "independent" from Marth. So she was NOT an exception.) are EXTRA's put in later on rather than being in mind during development. So don't think about them as wasted character slots, think of them as little extras. True, 1 new character might have been better than 3 clones. But I guess it could be worse.