Opinions are never popular with teachers. For many reasons.
As for the Big Bang? Observational time is too short to support any theory. Could be the expansion phase of bang, bang, bang where the universe pulses eternally inward and outward. Or the 'expanding' universe could just be an observational anomaly. Or we could just be a single atom in a grain of sand that just got smashed with a hammer by a very (very) big kid playing with his dad's tools.
What works is real. Whether you are navigating one of our starships between stars, or galaxies, or trying to locate a specific star with a telescope, or flying between planets in the solar system, you need a model of the universe that allows you to use its' particular mathematics to accomplish your feat successfully. Choose the model (theory) that suits your purpose and go with it (BTW, the flat earth model works quite well for navigating an automobile between cities. No theory is obsolete, they just get forgotten as a theory).
Reasons like it interferes with their work of turning you into a complacent, compliant sheep...Opinions are for the elite, the movers and shakers. All others should just keep quiet and do what they're told, think what they're told, and never question authority or an elite.
As long as the cities aren't over a few hundred miles apart, or are directly north/south or east west of each other.