It's not the first game to feature doing this and you certainly wouldn't play these kind of games without knowing that this is happening (since that's the main gimmick of these games) so you can't really complain about their behaviour when it's been made quite clear beforehand.

But if you really wanted to play this game without it viewing your porn collection / whatever, then you can always manage it with ACLs, chrooting or even virtualisation. It's not hard to sandbox processes and/or deny read access to specific sub-directories these days - even on home user orientated machines.

It might have been nice if someone had pregenerated a list of files from, say, a fresh BSD installation, and then randomly chose locations to put target files, and had that as an option (rather than using your own data).

Maybe, but what would you gain from that? You don't get paranoid traversing directory structures with bash, rsync, find, cmd.exe nor Windows Explorer. Nor do you complain about games that have file browser built in for loading and saving games (Eg OpenTTD).

These guys haven't been secretive about the nature of the game so it seems to me that the complaint here is strictly arbitrary.

BTW, given that it's GGJ game, there should be source code somewhere available (all Global Game Jam entries have to provide source code and all assets on CC BY-NC-SA or compatible license).

That's a bit over dramatic don't you think?

If you have a real issue with that then you probably should take it up with the lack of sand-boxing / fine grained permission granting in general purpose computers.