Fastest fix I've found for this one (secondhand, haven't gotten much playtime in):
keep training that tree, eventually you'll unlock the "Masters Degree" (I know, the skill training for "advanced" classes is P2W as fuck, but there's not much of a penalty for the debt system, you just lose a chunk of your future currency drops until either the debt is repaid or your character dies). That allows you to classify as an "Expert", and opens job offers as a class trainer.
Hope it helps.

The issue with Sakurai and why he's a jerk isn't because of what he absolutely refuses to it, it's his reaction to it and what he does instead. Let's take his excuse with Ridley, for example.

Instead of saying something like "We just don't see Ridley really fitting in with the rest of the group as an actual character", his excuse his "Ridley is too big" and "making him smaller would go against the character's origin." Meanwhile, Ganondorf, Bowser, and Samus (? Could be wrong on that one) are all different sizes from their "canon" appearance and Ganondorf is 70% a clone. He doesn't even have Dead Man's Volley and the reason he doesn't is because Sakurai likes him that way. There's no other reason for Ganondorf being like that, either.

Along with this, instead of putting effort into making better characters and characters that aren't another sword fighter, he makes "costumes" and makes them into characters. I.e Lucina, Dr. Mario, and Dark Pit. All three of them were pre-programmed costumes that they felt were just better as separate characters. And they are, don't get me wrong on that, but they put more effort into making those as separate characters instead of making completely new characters instead. Non-clones.

But that's just nit-picking. The last and most insulting thing Sakurai does is the Mii fighter costumes. Not only can you not use them in public games, meaning there's very little point in buying them since you can't show them off online, but they're character based. Genos, for example, is now just a really bad costume Seriously, they don't even include his mouth-lines. It's just his hat. . Even though he's been asked for since Melee, Sakurai decided the only explanation we get is him being made into a costume.

So, really, the reason Sakurai is a jerk is because he sucks at social things in regards to fans. Who knows if he even had much hand in choosing the characters you mentioned anyways. I'm 100% sure Bayonetta was not his choice, since it was the fan thing, if they're being truthful about it.