This is what I need, an explicit reason that makes one choice better than another. If hyphens make for a smoother experience, then I'll reconsider my default behavior.

Thanks for pointing out this benefit.

They suck hard. I use the renpy engine and there you reference file names directly but always lower case and spaces and hyphens turn to underscores. That can cause issues, so I just do underscores in my file names. Don't give damn about the web.