authors don't take into consideration how many curators will be splitting the 50%

Help educate them.

in some cases it could be the same person behind all those curator bot accounts anyway.

"In some cases" sure, but that is not typical of any sort of social platform with actual users. We have to think about these things in terms of how they actually work on a platform-wide basis not one edge case.

Anyway, that is not the reason why curation rewards need to be higher for the system to have a chance to work and that's a whole different discussion. It is useful for people to understand (to the extent they don't already or are being misled), that one piece (author's share) goes to a single user and the other piece (curation) is typically split up many ways with each voter getting only a tiny slice.