I would have to agree. It has been a point of discussion on the emulationstation github for quite some time along with issues of a similar type. https://github.com/Aloshi/EmulationStation/issues/191

For my system I’ve just picked all my favourite games for each system and have an ideal build for that and then when I get bored of them i’ll look in my repository for new games to add. I have emulationstation set up on my laptop for testing the games out before I decide whether or not they are worth playing on my raspberry pi.