The video kept referencing the "urban cowboy" look and lifestyle. That died out no later than 1980. There may have been some hangers-on in Houston and with those in the oil industry, but it certainly wasn't "mainstream" as the video suggests. People were still watching the TV series Dallas (fewer than a couple of years prior), but they weren't dressing like that anymore. For younger folks, the Magnum PI look -- polo shirts, etc. -- had taken over. Older (over 40) dressed conservatively.
The school "uniform" in those days was some shirt -- anything from a t-shirt (often a rock concert one) to a polo to a OCBD -- and...jeans. We would have killed to be able to wear shorts, even if it meant the longer variety that came out a decade later.