Yeah I noticed that, which is why I'm confused about this screenshot feature being invasive. Unless it's remotely managed, it would only be screenshots taken by you, and stored by you, in your time tracker.
Things don't need to be remotely managed for the user to lack control. The client software could take periodic screenshots during tracked time which are sent along when the user reports their tracked time.
That would make it centrally managed. Unless the user can override this configuration, we're talking about remote administration. Either through this tool, or through some other tool that deploys it and ensures the user cannot change it.
Kudos to the developer for standing their ground, but if we're talking about a remotely managed client computer then I don't think there's much the user can do to protect their privacy.
I'm interpreting it more like this is a standalone locally managed program, the user would like a screenshot feature in it.
But if you add remote management around it then this screenshot feature can be invasive, but then again so is the management software that prevents the end user from changing the config.
So the way I see it, the developer is getting upset over something they'd be unable to control.