I have to say, I find it interesting how many people seem to consider a wide range of class and race options to be so essential to fun. I can certainly understand liking the idea of a big range of choices sometimes but the idea that it's necessary every game, and that a lack of class and race options (or, in some cases, any curation at all by the GM) is considered some huge red flag that says the GM is probably lacking in many areas is a really alien idea to me (and an entirely untenable position when taken to the extreme position that some posters in this thread are doing).
I've run games where the only guidelines I gave to players were that their characters would be powerful figures in a fantasy world, in service to the king, and that they all needed to use or be magical in some way. Within those very loose guidelines, they could come up with anything they wanted. We ended up with a shape-changing dragon swordmaster, an intelligent magical sword, a character who could control and manipulate metal, and others I don't recall off-hand. On the other hand, if I ever get around to running Al Qadim, it will be with humans only, because when I selected it as a setting, I was looking for an Arabian Nights style game, not a D&D-flavoured Arabian Nights game, and I used the existing material as the framework to get me to where I wanted to go.
I'll of course work with players as much as possible, but in order to present a coherent world, it helps if there is single guiding authority, and my players trust me to be that. In my current game, I saw that one of my players was interested in dream magic and I offered them options to modify their chosen profession to make this easier -- they didn't even need to ask, I was simply able to see what they were heading towards and I understood the system well enough to see how we could better make this happen.
Conversely, in an X-Com game, I had a player suggest playing an alien defector. After careful consideration, I couldn't see a way to make that work plausibly within the context of the game, and said no. In the end, that player chose not to play at all -- not because the alien idea was rejected, but because, on reflection, they realised the entire premise wasn't that interesting to them and gaming in general wasn't high on their priority list at the time. (It's worth noting that no one was offended or upset here, we just wanted different things at the time. That player is back now, and has been entirely invested in our last few campaigns.)
When I'm prepping a campaign, the idea of aiming for some fixed number of race/class combos doesn't really occur to me -- I will include what makes sense based on the game idea I have in mind. Generally speaking, if a game has a lot of classes, I'm happy to include as many as I can, but I have no hesitation to remove something if it doesn't make sense or I feel it will be too much work to justify it within the context of the setting.
I'm not saying anyone is wrong for wanting a heap of options. People like what they like and, when they're participating in a leisure activity, they shouldn't put up with things they don't enjoy. I just find it strange that curation by the GM that results in a net reduction in class/race options is a complete dealbreaker for so many people. But perhaps this is just a variant of the whole "single game" vs "many games" dichotomy. Some people always want their games to have this minimum number of starting build options, while others are happy to try all sorts of different starting premises, some broad and others narrow.
That said, I know there are some cases where "I want lots of options" really means, "I have a limited range of characters I'm willing to play, and if the the GM is curating their setting, it increases the chance I don't get to play one of those characters." That's something I can at least understand intellectually, even if it seems a bit bland for long-term play, to me.