It's a specific case of a larger symptom: when you implement something in JavaScript that replaces default browser functionality, you also have to re-implement

It's a specific case of a larger symptom: when you implement something in JavaScript that replaces default browser functionality, you also have to re-implement all of the related error handling, edge cases, etc., and can't rely on the work that has already been put into making things work correctly in the browser. But in practice, JavaScript developers never fully re-implement the features that they replace, which means all that work on the browser has gone to waste.