Less silly than it looks at first sight. After all, for day-to-day use (except for GPS I guess, and most people probably don't even realize it would not work without a correction for relativistic effects) relativity is very little gain over classical Newtonian physics and a lot more complex to work out from a mathematical point of view.
So even though 'that's how it really should work' we tend to take the shortcut because it is 'good enough' for almost all use cases.
Which caused us to miss the wood for the trees for a long time. This minor change is what enables learning in the first place, and as such it could easily be a game changer.
