actually, instead of the object hash, you could also use the commit-hash. then the filename would be mandatory, but the url would be more readable and usable: give me the file VERBS.md as it is at commit <hash>
Which target audience of github needs extra verbosity in the commit hash, though? Once you know it you know it; if you don’t know git you aren’t the target audience; etc. Saying /user=foo is no better than ?user=foo if your audience can work it out without confusion from your unadorned paths. We have a great deal of history with filesystems showing that people are capable of keeping up with paths that lack key names if exposed to and familiar with them, and if the filesystem isn’t being constantly randomized.