You are just wrong and yet a bit right. The models we use to explain concepts like molecules, heat and other science subjects never is able to convey the whole story. In those models often we make some assumptions or it has yet to be further researched.

The models for atoms has been revised quite a few times, but mind you that the different scientist making these models all had new findings and created a model that adhered to these new findings. Just to add to this, John Dalton created the sphere model for atoms and just 4 years later Thomson added to this with charges. This was in 1800, by 1926 some dude called Schrodinger came in and wiped his behind with most of the strict rules of the models and that model is still used to this date. Still this model is also flawed, as a lot of students will believe that it "looks like the pictures".

Tl;Dr Models are made to explain complex mathematics in a visual way whilst making some assumptions

Sauce: was a physics teacher some years ago.

Disclaimer: WAS a physics teacher, sorry if I made a mistake and ruined someone's day

Maybe they're talking about ideal gas? That's just a physical concept with these assumptions. But it's not real.

You should talk to better physicists because that isn't true.

High school teachers by definition are teachers, not scientists. The textbooks used in high schools use simplifications to introduce concepts to developing minds. There is no way a school teaching teenagers would get into the complexity of theories governing our reality.

Have you surveyed a large percentage of all high school physics teachers, or are you just projecting your extremely limited personal experience onto the rest of the world's physics teachers?

My high school physics teacher would always preface by explaining how the lessons and experiments are only valid in a vacuum.

What people fail to unterstand, physics teachers included perhaps, is that physics doesn’t describe reality, but models of reality.

As a physics teacher (not kidding here), if you want to be taught straight out the electron wave functions in 3 dimensions in high school you might consider not doing undergraduate physics. And I don't think I'd bother being a physics teacher when more than 90% of my class don't understand what I'm talking about.