It does give you the feeling that you don't have a complete character, even if that may or may not be the case.
I don't agree with this at all.
Previous games most characters only had 3-4 special moves.
Raiden - Superman, lightning bolt, teleport, shocker.
Kitana - fan toss, arse, fan lift.
Sub - ice ball, slide, clone, ground ice or ice shower
Scorpion - spear, teleport, air throw
For those 4 characters at least, they have one variation that has those moves, or something very close. So in terms of not being a "complete character", you're saying they've always been that way?
So now that we've got the option to add/change some moves, or a variation that could potentially play like a completely different character, apparently they aren't a complete character?! WTF? What sort of logic does that stem from?
The MK11 gameplay may change things, eg: kitana's fan throw juggles, but that's another topic.
I think this is people feeling that they're missing out on something that's in the game and that they've lost out by not being able to use it... even though it's playable in casual matches.
If there were no variations half of those extra moves would never see the light of day because most characters wouldn't have more than 5 equipped anyway.
If there were no variations in MK11 and most characters had one or the other of the current variations, would people still be complaining as much? Possibly, but i don't think so, simply because they don't feel like there's something in the game that could have made it better. EG: Kitana up fan, scorpions misery blade etc.
Customs definitely change things up, but not being a complete character... no.