Given current events the weaknesses of ERCOT become highly visible:
Why weren't generators winterized before Texas winter storm? | khou.com
Interestingly not all of Texas neglected winterization:
El Paso spared rolling blackouts partly due to being outside ERCOT system | KXAN Austin
Following the infamous 2011 winter storm, ERCOT studied the issues and did nothing while El Paso Electric winterized their production and distribution systems. The results are clear.
The prime culprit appears to have been resistance by producers, who did not want to spend the money needed to winterize nuclear, wind, batteries, gas lines, gas generators, coal or anything else. As a result when they were needed peakers could not operate and few producers could operate. Even emergency generators were not winterized. [Bizarrely, some completely renewable interconnected systems went off line because their generation had minimal demand side and the load management systems were too antiquated to cope with overloads of production without shutting down. Most current technology load management systems can deal with this if programmed properly.]
Predictably, perhaps, renewables opponents from the Governor down all first blamed renewables, although several included other sources too.
The aftermath, this time seems likely to be somewhat more forceful. The producers are powerful political contributors, though, so to remains to be seen what happens. Contrasting non-ERCOT areas from ERCOT ones seems likely to spawn a lively debate.
Summary: privatizing grid, sources and types does not eliminate the necessity for high standards that apply to all participants. The EU has some relevant standards, as does the UK and a few other places. Whether those are used is another question. Similarly, the current mess has shuttered the majority of the Mexico electricity also, especially since much of the gas now comes from a recently activated Texas pipeline. Naturally, none fo it had been winterized.
Future note: given the reality that Arctic warming is one of the most extreme on the planet, we can expect that regular and dramatic collapse of the polar vortex will happen, resulting in more frequent extreme weather from Greece (take a look at the Parthenon this week) to Northern Mexico to everywhere in the direct northern path to those places. That happened in 2011, now is happening and certainly will happen again in less than another decade.
Winterization and Summerization both are urgently needed for ERCOT and most global grid suppliers and uses. Battery storage and renewables can help greatly but the traditional sources must also be adapted now!
Right now versions of this story are being discovered in many places. National governments and transnational regulators have little time to fix this set of problems.
All these things were predictable and avoidable.