Isn't that a result of ERCOT stubbornly refusing to interconnect with the rest of the national grid, out of an irrational fear of coming under federal regulation?

I suspect that trying to be self-sufficient works most of the time--but when you get to the edges of the bell curve locally, your ability to be resilient and survive depends heavily upon your ability to be supported by others around you.  This certainly holds true for individual humans; I suspect power grids aren't that different.