The mayor recognizes a political opportunity when he sees it. He'll threaten to stop funding until the backers give him a nice share of the spoils. He does appear to make a rational case on behalf of the people of Tijuana, but a little graft will change his tune.
(The above is just my opinion and speculation without any supporting documentation. Politicians are parasites.)

Defunding them or not, the UN, the open borders marxist group and of course...georgie poo sorass will continue to fund and direct these useful pawns.