Kuvult, when we were kids television was prohibited. Don’t know what you’re talking about. Kashrus standards were pretty strict. 40+ years ago Yeshivos enforced Kashrus standards and asked everyone every year whether anyone had a TV. Triangle-K was a big no-no since Rav Moshe Feinstein’s time, and famously so.
Chasidish and Yeshivish kids mixed because both more or less shared strict Kashrus and no TV. MO even back then was a different world.
Hashkafa must be in harmony both at home and in Yeshiva.