The main power of a maintainer is to reject code. Once it's merged, it becomes the maintainer's problem. So if they don't understand what's it's supposed to acc

The main power of a maintainer is to reject code. Once it's merged, it becomes the maintainer's problem. So if they don't understand what's it's supposed to accomplish, or how exactly it works, a good maintainer should reject the code. Merging stuff blindly is just asking for trouble. Sometimes yes, it happens that somebody sends you code that does something you're not familiar with, like interacting with weird hardware you've never seen before. It's still the right thing to do to ask lots of questions about it, so that if that part of the code runs into a problem later you have some sort of idea of what to do about it.