Yes. Very much so. What gives people the right to upload entire games, slap some commentary over it and then profit. Developers deserve a share of the money made. Not all of it, but some of it.
It's quite simple really. If you use a clip from a TV show or a movie in a different TV show or movie, you have to pay royalties. If you use a sample of another piece of music when you're creating music, you have to pay royalties. Here you're using a video game to create a video and so logically royalties should be paid or revenue earned should be shared.