This is sort of off the subject, but I feel like it is incumbent on the GM to help provide spotlight time for players. That means, though, that players building inappropriate to the campaign characters impacts more than just themselves. It is potentially disruptive to the game they signed up to play.
Let's say you are going to run a thieve's guild, morally ambiguous criminal campaign. Do you let a player come in with a Lawful Good paladin intent on doing the Lawful Good paladin thing? I wouldn't. I might work with the player to come up with a paladin concept that can work with the campaign theme, but I would not want to have to constantly be dealing with the out-of-place character and their reactions to the group's criminal activities, etc. In short: I don't think players have the right to play whatever they want if they have agreed to a certain style of game. It is their responsibility to create a character that works with the campaign premise.
That's an extreme example, of course, and I don't expect any subclass absolutely could not work in a city campaign, so in essence I agree with you: as long as the player is still accepting the premise, they should be able to play what they want. But I don't think there is anything wrong with a curated list of things that would "work best" to give the players some guidance, either.