Registering is one part of a thousand part process. Ask a small business owner, other than geography, would you rather operate in California or Texas. 9 out of 10 will say Texas.
Also, when I was still at a firm providing tax services to companies large and small (including a number of YC companies), I had more than a dozen clients move to CA from TX, and only one company move from CA to TX. They moved because Texas simply wasn't a viable place to do business unless you're in oil or energy (and the one client that moved there was in energy).
Texas is where companies go when they aren't strong enough to survive real competition.