Yeah, it's a weird move to legislate this kind of trade-off, especially when one of the competing factors is tire wear. Making new tires takes energy too! If I was paranoid, I'd say the tire lobby was involved here and looking for an excuse to sell more lower durability tires.
This is 100% how legislation gets written when none of reps have experience and the only calls they take are from lobbyists.
It's easy to imagine the manufacturer reps are playing games with the lawmakers. "Oh no, this is going to be really hard on us! It's going to cost us so much money! But I guess we can comply if we have to."
Apparently many new cars come with tires with less than normal tread, one of the reasons is to have greater fuel economy.
This was 100% pushed by a lobby. Name me one legislator who has any detailed knowledge about tires, rolling resistance, traction, tread wear, and fuel economy. I guess there might be single-digit numbers of them in a state as big as CA but even there I'd be surprised.
And even if this was originated by an eco lobbiest group, tire manufactures would love regulation that forces everyone to buy more expensive tires.