It is not super common. Especially if you fill regularly and run the truck weekly. The heat from running the engine keeps the fuel warm and kills any bacteria. Plus the fuel doesnt set long enough for a chance for it to grow, if there is moisture present.
See it alot on RV applications or when equipment is used seasonally. Alot in climates with rapid temp and humidity swings where theres a chance for condensation to build inside of half empty tanks.