What we see may not be what Sakurai sees, Lucas was already unique enough from Ness, yet still borrowed some moves. If even Lucas can't be unique enough, then there isn't very much else to go on, particularly for Claus. Pokey can't really do anything outside of his mech, and having him fight in his mech is a bit unfeasible, while Giygas is just completely a fan idea, a swirling mass of red isn't much of a playable character. Giygas lost his bodily form, which was Giegue.
I'm not quite sure where you're getting the idea that Claus and Porkey aren't feasible characters. Porky, perhaps, but Claus has plenty of potential thanks to his sword, PK abilities, arm cannon, and of course that big lightning bolt he uses. They wouldn't have to make up much to make a workable moveset, and I don't think that's the reason for his absence on the roster. Speaking of which...
Again, Falcon's moveset is completely made up, Goroh only has any sort of viability due to having a sword, he'd still have to have an entire moveset be BS'd out of nowhere. As for KI characters, it'd be really doubtful to get more than one character from a series at once this time. Viridi is better than the other choices anyway.
I don't think having a moveset made out of nothing is a bad thing. We have plenty of characters that already do that, such as Falcon, Ice Climbers, R.O.B, Rosalina, etc. All of them have movesets that were more or less made up. You can't just say it works with all these other characters and then say Goroh is an exception and should be excluded because of it. He at least has more to work with than Falcon did. And as for Kid Icarus getting more than one rep this time around, plenty of other series have gotten more than one rep in one installment. For example, Kirby got two characters after having only one for the last two games. If representation is not an issue, then the fact that we have so many great Kid Icarus characters now means we should have no problem introducing more than one this time around. However, I still think representation is an issue, and therefore we probably won't see more than one.
Well you just helped my point, larger series don't get more characters just for the sake of having more, they get whatever is viable. Of course, fans want Ridley, but Sakurai has said that he would have trouble with it, which is probably why he hasn't tried it before. Star Fox gave two easy clone-like characters, particularly Falco who only got in because he was a clone, it has three characters now because it was easy to slap Falco and Wolf on at the last minute. Krystal being added this time wouldn't be giving Star Fox more attention, it'd actually be Sakurai not giving Star Fox the shaft for once with the notion of "there are only clones in Star Fox."
Yeah, we shouldn't add characters for the sake of simply having more characters. We certainly shouldn't add in random enemy #42 as a new character for the sake of having a new character. But I digress.
I guess the main thing I'm trying to say is that, even if there are good characters in a series, that doesn't mean we have to add them in, and I think representation is the reason for that. There's a reason why we have more Mario, Zelda, and Pokemon characters than all the other series, but at the same time, there's a reason why we don't have every good character that has ever existed in those series. Those series are deserving of having those large selections of characters compared to the other series, but there are plenty of characters from those series that will miss out because we can't just add in every good character from those series. Star Fox, the way I see it, is not as deserving of as many character slots as bigger series, and just because Krystal is a good character from that series who would be a unique fighter in Smash, that doesn't mean we have to add her in.