I think the parts of Texas and California with tech jobs are... not substitutable for a large part of the tech workforce on political/social grounds.
I do agree that higher density and public transit would help make California better by my standards more than requiring rooftop solar... but at least in the higher density parts of California where I am? I don't think requiring rooftop solar will make much difference. If you have a large multi story complex, adding rooftop solar won't do a lot, but it also isn't going to add significantly to the cost of the building, just 'cause there isn't much roof compared to the rest of the building.
In the high density parts of California that I want to live in, single family homes are already the domain of the rich. Personally, that's okay with me; I don't need a single family home, and I think we should be focusing on building more condos in the high density parts of the state, and as I said, requiring the roofs to be covered with solar isn't going to significantly change the cost of building those higher density buildings.