It was not a wizard build. It was an alternate version of the wizard with very different flavor and features - not something that could be simulated by a subclass in 5e.
It absolutely was a wizard build. From Heroes of the Feywild:
Heroes of the Feywild said:
The following section presents new powers for wizards with a strong Feywild theme, as well as a new wizard subclass, the witch.... A witch is a type of wizard, a class introduced in the Players Handbook.
Sure, they had some variant features and abilities, but their actual powers were all wizard powers, available to other wizards as well; and they could take existing wizard powers just like any other wizard could. Even some of the abilities that were built into the witch were available to other wizards- coven abilities, for example.
As to whether it could be simulated by a 5e subclass, I guess we have to disagree. I'm really not sure what you think they got that other wizards couldn't. Their starting class features included a familiar (check), cantrips (check), and a coven ability that any other wizard could choose if they desired.
They did get augury, I guess. But that is literally the only thing that they got that other wizards didn't. If you can't fit a single feature into a subclass, I don't even know what a subclass is for.
"class bloat", to whatever degree it can be argued as an actual problem in 3x, is an irrational concern for 5e. The mere existence of the subclass system is enough to keep it from ever exploding out of control as, unlike 3.5 which lacked such a system, most concepts will be developed through subclasses.
I answered this upthread already. I disagree strongly with the assumption that focusing on subclasses automatically prevents class bloat. It has so far, yes. I'd like to keep it that way, personally.
I would expect something like Pathfinder 1e, which periodically released new classes, but did so in a controlled way and only with concepts sufficiently broad to exist as full classes with lots of potential design space.
When I look over a list of the base classes in PF 1e, I have to say, a ton of those don't even come close to what I consider to be "concepts sufficiently broad to exist as full classes" that can't easily fit inside of existing base classes.
Alchemist? Sounds like an artificer subclass. Cavalier? Fighter. Gunslinger? Fighter, or possibly multiple subclasses for different classes. Inquisitor? Sounds like a cleric or paladin with an attitude. Magus? Really? Omdura? Isn't a divine warrior a paladin or maybe war cleric? Oracle? We have a divination wizard and knowledge priest already. Etcetera.
Now the shifter is a concept I can see as a base class. But that's the only one I am aware of that really fits my criteria for a base class. It's something that truly can't be done with existing classes.
many class concepts work well as subclasses, but many do not and are worth developing as their own classes if they are to be developed at all for 5e. Psion is a prime example of this.
I think the primary point of disagreement is that you think many concepts need or deserve development as base classes, while I think very few do.
That said, I'll repeat that I agree that the psion/psionicist needs and deserves a full class, but I also think that psionic subclasses will do the job for psychic warrior, soulknife, etc- in fact, I have had both of those built as fighter and monk subclasses for my campaign for a couple of years now.
If WotC wanted to do almost exclusively subclass development, they should have given that treatment to several of the base classes that would work as subclasses for the primary four.
Clearly, given the existence of the artificer and the UA mystic, they don't want to
exclusively develop subclasses. But they definitely want to avoid class bloat, as evidenced by the fact that we've only seen one new full class since 5e launched.
I do agree that there are a couple of base classes that could easily be subclasses (especially the paladin and ranger). But tradition carried a lot of weight during the design process and playtest of 5e, and one of the lessons learned from 4e was, "Don't make the player base wait for a year or more to have the stuff that they're used to seeing in the Players Handbook." I think that the fact that e.g. rangers have been a base class in every edition of the game since 1e made it inevitable that it would see use as a base class in 5e. The witch, psion, shifter, etc. just didn't have that level of cachet.