I know cows that offer parts of there body to customers before heading to the kitchen to be made it to meals for said customers.(Restaurant at the End of the Universe) Yukkuri that are bred to be docile and not runaway are easy to imagine.
Probably. But there's nothing suggests that's the case here, and I can't remember seeing much material where the yukkuris don't mind being treated as livestock/food. Let's try not to talk certainly about additional context where there is none.
Also, restaurant at the end of the universe was from something quite different from yukkuri fandom (and not involving yukkuris at all). Using something that isn't a yukkuri to establish how one might behave doesn't relate that well.
I was giving an example of then power of selective breeding in a fantasy setting to reinforce what I have already posted. With yukkuri there is little need to restrict ones self to old ideas, as yukkuri have no true canon.
It's true that there is no definite canon, but that's not even part of it (neither is the situation the same. Marisa clearly isn't offering herself to be eaten and is shocked at the prospect). The final point is that just because something is bred to be livestock it definitely doesn't automatically become incapable of running away.
Simper explanations: 1. The Marisa is paralyzed with fear. 2. The Marisa is experiencing the "train wreck effect" and can't pull itself away from watching what happens to the Reimu, despite how horrifying as it is to it.