It thoroughly depends on the use case. If someone's submitting a documentation change, I have no problem at all merging in with the merge button. It's perfect.

It thoroughly depends on the use case. If someone's submitting a documentation change, I have no problem at all merging in with the merge button. It's perfect. I think the button should be used sparingly, but I'm extremely happy that it's there. Small changes to a non-crucial project shouldn't be that big of a deal. Bigger projects typically have a more proper master/develop branch structure, and that unstable branch is there for a reason. Also, GitHub is often used privately by trusted teams, so merging a repo from a colleague or coworker without testing first could be proper in many situations.