I don't like anti-natalism for the same reason I don't like anti-theism and militant veganism: It isn't an effective strategy for convincing people, and does little other than make people more set in their ways due to the backfire effect. [0]

A lot of this conversation leads from the millennial baby bust. There is a podcast called "Chapo Trap House" that talked about the baby bust ( they are pro-natalist if you were curious ), and I think they put it well:

We have stopped believing in the future. Constant economic downturns, the rise of fascism, the continued destruction of our environment and seemingly NOTHING being done to fix any of it.

We don't have ANY WEALTH. The ultra-wealthy have sucked up all excess capital in the country and people are pissing in bottles while being chirped at from their smart-watches while making pathetic pay. All of this so they can go home to their house where they have multiple room-mates.

We would rather not have children than watch them starve in the event of any number of possible ecological doomsday scenarios end up happening.

0: Nice pamphlet effect about the backfire effect: https://theoatmeal.com/comics/believe