keeping them open sounds like a power move and potentially a bad idea if someone can find a way to circumvent the visitor debuff so yeah, same here I'd leave mine closed
The question isn't about keeping them open, but about being able to keep them closed without needing to carry a master key or setting up a multi-gate airlock system so you can come and go with a slave key.
Opinions expressed in this statement are the authors alone and in no way reflect on the game development values of the actual developers.
IMHO interaction with gates (open/close) shouldn't be prohibited by visitor, this would remove a whole class of exploits (especially the ability to combine a stick fence with a pclaim to perfectly secure cave entrances).