I don't love the concept of "clone" (I find it a bit charming, though), but paradoxically I prefer Lucina than Marth, Dark Pit than Pit and overall Dr Mario (one of my favourite characters) than the plumber
...btw, I still prefer Mew than his clone XP
I see nothing wrong there. I far prefer Dr. Mario over Mario, but that doesn't necessarily mean I like him as a clone. I'd much rather him have an original moveset instead of a Mario clone. Dr. Tornado being retained was a step in the right direction for Doc.
However, given that Sakurai said characters who aren't unique enough to be their own character will be made into Alts., it's a little upsetting to see the Koopalings and, in particular, Alph be relegated to Alts., yet see Doctor Mario, who is literally Mario in a Doctor getup, and Dark Pit become new characters. It just doesn't add up.
Also, I believe the reason Dark Pit is getting the full force of the clone hate is because he's about as close to a carbon copy of another character as you can get. There's little difference in their movesets, his appearance is near-identical to Pit's, and, perhaps most of all, he's from a game Sakurai designed. It makes it seem like the reason Dark Pit was added was because Sakurai wanted a character from one of his own games. That may not have been the reason, but all the other points stacked up on it make it look like a lot of Sakurbias.
Also, I think the reason Doc and Lucina are getting a pass is because Doc is a veteran and is basically Melee Mario, and Lucina because her unique sword mechanics make for an entirely different playstyle.