Um, yeah it can be dangerous. Consider the physics of pulley systems, where it's quite easy for intuition to lead into the trap of considering gravity "canceled" in some places, which can cause major problems when the pulley starts to move or when the forces are not all linear. Thankfully people who actually design cranes and such get that stuff right, but it's conceivable that someone who gets it wrong could cause serious physical harm to people/places/things.
Furthermore, perpetuating incorrect physics or math principles (outside of limited audiences of physics/math geeks) even as a joke can lead someone to take the incorrect concept to heart, get frustrated when they have a need to solve a related problem, and possibly even arrive at a dislike or distrust of science when their intuition causes them to take erroneous leaps and they therefore can't verify for themselves "standard" scientific results.
Same general idea as something that came up on THR.org a while back, when someone whined about incorrect unit representation and someone else whined about the first whine. There are potentially serious mistakes that could be perpetuated by casual use of incorrect physics concepts (or units in that case).
I had some teachers in later middle school and high school who demanded correct units everywhere and took it seriously when students made stupid errors due to faulty intuition on physics and math problems, and if anything I wish they'd have been more draconian even earlier.
