I can only see one big glaring problem with clones. Great characters end up being introduced with a boring and samey moveset and are stuck with it forever.
See Ganondorf, but also Luigi, who could've had a totally different and more original moveset from the start. I feel the same for Dark Pit, I wish he had a more original moveset, especially with the humongous amount of weapons present in Uprising. The biggest problem with clones is wasted potential.
I kinda of agree with this. When adding clones to pad the roster, it's better to pick clones that make sense. Ganondorf is the perfect example of how not to do a clone.
However, despite the similar moves, characters like Falco and Luigi have becomes completely unique characters in their own right. They're similarity to their counterparts actually makes a lot of sense. In the case of Dark Pit, I feel safe saying that he would have never been playable if they didn't make him a clone. If he becomes unique in the future remains to be seen.
Hmm, so the question is whether or not people would rather have 51 characters with clones or 46 unique characters. Do people think cutting Ganondorf, Dr. Mario, Falco, Toon Link, Dark Pit, and Lucina would be worth it?
Yeah it does depend on preference here. However, keep in mind that characters like Falco and Ganondorf are not Melee clones anymore. Their movesets maybe similar, but I believe the effort that goes into them is the same as any other unique character now.
The way I see it, more characters makes more fans happy. If you could add a clone that makes sense, then I say why not? Lucina fans and Dark Pit fans get to have their beloved characters in Smash without any effort.