While I understand your point, those new residents don't generate new taxes instantly. Development itself takes time - residents trickle in. And one years worth of taxes likely isn't enough to fund infrastructure.

So, if there's no kick-in from the developer, it could be years or decades before funding is in place.

I agree that it's not (directly) the developer's problem to solve. But, to the extend it might make their development faster or possible, they should have an interest in kicking in funds. And communities should rightly ask for that money.