Universal Meditech Inc one of the companies referenced made covid rapid tests, so the most charitable take on this is it was a sloppily run lab trying to make money on covid tests. There's a recall notice the FDA issued, so they did make something. https://www.fda.gov/safety/recalls-market-withdrawals-safety...
I'm sure there are more reasons, but modified herpes and HIV have both been used as experimental cancer treatments.
Edit: It appears they made a variety of in-vitro tests during their peak operating period. For diseases, pregnancy, drugs, etc. So probably more about "criminally sloppy lab" than any more movie-worthy motive.
Secret COVID HIV rats is a Bond villian thing, not something actual criminals do to make a buck.