Yup, all of this.
On the taxes, people have this belief that millionaires don’t care about taxes, when time and time again we see that they do. People are free to disagree that millionaires should care about taxes, but CA’s insanely high tax rate for top earners (in comparison to many other states) is a negative for the guys who have money as a big motivation, which is clearly the case with Rantanen. Signing in Dallas or Tampa would be like getting an extra year of salary from signing in LA.
You are right too, politics does matter, I don't want to get to deep into it or start any arguments, but CA has a very polarized image in this country, one that usually depends on which side of the aisle you side with. Not saying anyone is right or wrong, just dealing factually. To be fair, there certainly also guys that would be turned off by Texas or Tennessee too.
I think you also left out the winning aspect of it for some guys, some guys like Rantanen who are all about the money, while others care more about winning. The Kings have not won a playoff series in a decade, most players in the league right now have never seen this team win a playoff series their entire careers.
So you miss out on any player who cares a lot about money, any player who cares the most about winning and you miss out on some others who my not be a fit culturally. It's no surprise that the Kings struggle to sign FA's. They are fighting an up-hill battle that for the most part isn't their fault.