Unfortunately, the court system is not friction-less enough for "your weeds got in my yard" to be a remotely workable reason to go to court. It would be nice to live in a society where justice flowed as freely as municipal water and common law obviated the need for all other forms of organization or regulation, but in the real world going to court is so expensive and time-consuming that we need a lot of other forms of power around to avoid overusing that method.

If you have a plan for reforming the local judiciary to be so effective that HOAs are no longer necessary I am all ears, but I have not heard any proposals for doing that.

You don't need to go to court. Most cities will be happy to fine your neighbors for "harboring pests".