My issue with Isabelle is not that I wanted any particular character more--I mean, I did, but that's not my issue. The problem is that I just wanted someone more interesting. I didn't have any attachment to or prior interest in Simon, for example, but when I saw him I thought "oh, he's kinda cool. Unique weapon, interesting playstyle, and he brings a whole new franchise into the fold. Good deal all around." It helped that K. Rool was shown after as well, but even if Simon had been it, at least it would still have felt satisfying.
Isabelle is basically a slightly different Villager. Much like many semi-clones, there's not much weight to her announcement. And yes, I may have gotten a bit too hyped up, but really, that would not have happened had Sakurai not been injecting hot liquid hype into our veins since Ultimate was announced. You can hardly blame me for expecting a megaton when there's been nothing but expectation-shattering reveals so far. I don't mind that she's there, and I'm not going to start spewing the tired "slots" or "deserving" arguments against her, but revealing Isabelle, as a semi-clone, on her own, after freaking K. Rool no less, is like throwing ice water on a raging inferno. I'm not sure when a better time would've been...but not then, man.
Granted, I'm sure there are many people this IS a megaton for. That seems to be the case anywhere that isn't Smashboards. And that's fine. But that doesn't mean I can't be disappointed, or show my dissatisfaction with a character reveal (not the character herself, though I'm pretty hard neutral on her anyway.) That also doesn't make me petty, or only hating on a character because my own wasn't shown. I'm bummed, simply because I find this particular reveal uninteresting in this situation.
At least now my hype is dead, lol. Maybe that was the whole point--cooling off the fanboy fire. That could either mean the rest of the reveals are similarly lukewarm, or it was done to throw us off a super-megaton later. I think I'll be safer assuming the former...