Not a compelling argument, I will always make sure this doesn't happen.

And I also distinctly remember being unable to drop my bag at EWR for being "too late" to do so.

Always better to be early, so people will factor that in.

> And I also distinctly remember being unable to drop my bag at EWR for being "too late" to do so.

That is indeed a universal thing when you have bags to check. I just don't consider that a "have to" since you don't have to check a bag to fly.