Most of the software companies in Memphis are probably selling to relatively local customers, thus tying their income to the local markets. The software companies selling to everyone everywhere are in the big tech hubs.
You're probably not terribly wrong there if you're specifically speaking about software companies, but the largest employers in the area are multi-nationals.
FedEx is headquartered in Memphis, as is International Paper, AutoZone, etc.
Of course, they aren't exactly software companies.
