For some reason, .NET is extremely popular outside of major tech hubs (notably in Europe), where you're much more likely to work for (without loss of generality) Ikea than for Google.
The Dallas area is a major tech hub. It’s just an older hub of major enterprisey type companies with major tech divisions there like Texas Instruments, AT&T, Bank of America, defense contractors like Lockheed, etc.
Office Space took place there before the dotcom bust.
Less enterprisey, but John Carmack and id Software also started there.
I lived and worked in Atlanta from 1996-2020. Those aren’t anymore tech companies than Delta, Home Depot or Coke by modern definitions. In all of the companies you named, software development is a cost center, not a profit center - follow the money. Who gets paid the most as a group at those companies? Those are enterprise companies.
Aah that explains it.
For some reason, .NET is extremely popular outside of major tech hubs (notably in Europe), where you're much more likely to work for (without loss of generality) Ikea than for Google.