The article finds fault particularly with the national standards not being adequate, and specifically points out that the standards in Texas are more strict than the national standards. He goes on to give some details on the enforcement of those Texan standards. In this case, following national standards as opposed to Texas's standards would have led to an even worse disaster.

Your claim that being on a separate grid caused the outage is too strong to be supported by the data in the article, which is why he doesn't make that claim. Additional data could come out either in favor of or against your claim: although the interconnect bandwidth was fully utilized (edit: txlpo78 points out that it was not fully utilized), we need solid data on whether Mexico and the neighboring states facing similar struggles could spare significantly more capacity. If not, then having more interconnect bandwidth would not have helped much. If they had power to spare, then the interconnects were indeed a problem.

No one is attacking regulation. Virtually everyone I've seen is in agreement that better regulation is necessary in this situation.