alt Hacker NewsYeah, because there are a lot of mechanisms by which a folder may start to execute code when you open it outside of restricted mode. A large fraction of addons have something which could be used for this, for example. There isn't a general check that it can apply ahead of time for this.
(They could, with some breaking changes, maybe try to enforce a permissions system for the matrix of addons and folders, where it would ask for permission when an addon does actually try to run something, but this would result in a lot of permission requests for most repos)
They could also, with a breaking change, enforce addons register what sorts of files they'll execute when a folder is opened in trusted mode. If no matching files are found, then opening the folder is safe and no prompt is needed. If matching files are found, then prompt the user and replace "may" with "will". Fewer permission requests, and a clearer message.
People will still inevitably ignore the message and open everything in trusted mode, but it'd be more reasonable to consider that user error.