Alright, let's go point-by-point
Edit: Note that I say "clone" for brevity but am including any character that heavily reuses animation assets.
The time is better spent on actual alt costumes and further polishing the game.
There's something being left unstated here and it confuses me. Do you think Lucina would be better off as a Marth alt? Should Falco have been a Fox alt in Melee? I don't see what that accomplishes other than being a strict subtraction of the game's content with no benefit. As for polish, I'm going to give you the benefit of the doubt and assume you don't mean art because, again, that's not relevant. What that leaves is mechanical polish and, in that regard, I don't really understand what you want them to do that clones are preventing them from accomplishing. While a game should be well play-tested and not buggy, Smash is already pretty good about that, it's just that, like all games, eventually it gets broken because no team in the world can test a game as much as it's tested by players in like its first week of release for a game like Smash. Not only that, but skipping ahead, you noted that we are in:
In the era of DLC, post-game updates and patching
So a game not being perfectly playtested (and even Melee somehow still probably isn't) is even less of a problem because any issues can be fixed after release.
But I don't think any of this is necessary, because I see no reason why clones should make that or any related problem all that much worse.
You support clones and I’m against them. We’re on completely different sides so we’ll never come to an agreement.
Not important to the argument, but I find this to be a bizarre way of looking at things. It's weird how relativism leads to absolutism...
Clones were a practice done in the past as a way to pad out a roster to give the costumer as much “content” as possible since games couldn’t be updated or patched post-launch.
I don't think that this is exactly accurate, but it's also irrelevant, including for the reason you mention immediately after, so this has no function in proving anything.
In the era of DLC, post-game updates and patching, the developers are better off must focusing that “extra time” elsewhere.
And you continue to say things with doing anything to complete an actual argument for them. What's the difference between Falco as a Fox alt and Falco as a clone? The involvement of programmers in changing framedata and so on. Anything that is going towards art is being contributed by other people, so it makes no difference. It's not like those programmers would instead become artists and we'd have 10 new costumes if they didn't need to give Falco's neutral special hitstun.
I mentioned actual alternate outfits due to the fact that it’s been one of Smash’s main weaknesses. What Smash gets for the most part are quick texture color swaps.
Here's the difficulty in this being turn-based, I guess, but it can be seen from my previous comments that this is a non-sequitur.
They contribute nothing but needless roster bloating in my eyes.
You're just repeating yourself without addressing the point.
The characters in question deserve better.
If the choice is between costume and clone, how does that even matter? Does Falco being a skin of Fox do something to preserve his integrity that him being in his own slot with his own play style fails to do?
If we go by your logic, we could end up with over 10 Fox variants/clones just by tweaking the properties.
I try to avoid shouting "Fallacy!" but that's a slippery slope argument that doesn't prove anything about the claim that I'm actually making, in part because it makes assumptions that I never did (such as that the same character can be successfully iterated on more than once). If you want to push what I said farther, a much better analogy would be:
If we go by your logic, we could end up with over 10 more clones of other characters just by tweaking the properties.
That's a more fair representation of my logic, and you know what? I agree with it. If there are enough characters out there that could justifiably be interpreted as clones and would otherwise be alts for those characters, I'd be all for it. There's no benefit to, for example, keeping Alph as a costume as opposed to letting him be his own character who uses the new Pikmin types while Olimar goes back to using the ones from 1 and 2. There's the same amount of art work being done, but also more gameplay potential added. It seems like a win-win.
That feels like the developers would be cheating off a potential costumer. That is what I’m against.
You personally might react that way, and other people undoubtedly would, but a lot of those
other people are the sort of idiots who think clones take up slots that could have been occupied by a completely original character, which is just false.
In addition to all of this, I should also point out that clones do an excellent job of setting up for future installments since, as we've seen, characters introduced as clones tend to have more done to distinguish them in a later title, as happened with Falco.