Well that is the time the bearded wonders and the film renaissance were early on and changing things in the American Filmaking climate.Did anything good come out of Hollywood in the late 70's except Star Wars?
Alien is considered pretty darn successful/good critically and commercially.
A lot of comedies like The Jerk and Animal House.
People love Grease. Not my thing but apparently it is good.
Some pretty good things considering the recession's effects were taking hold and the old generation was dying off.