I think OOP helps to build loosely coupled systems but it doesn't protect you from tight coupling. You have to know what you're doing.

I think OOP languages made some pragmatic decisions. Sometimes a feature which is harmful 95% of the time could be genuinely useful and safe 5% of the time... Some languages like Haskell might choose to not allow that feature at all and force the developer to find another approach which is almost as effective for that 5% of cases; that's fair enough. It's a different philosophy.

I feel like that about passing mutable objects by reference. I find it harmful most of the time but there are rare cases were it's convenient and beneficial. I've worked on open source projects were I wanted the user to be able to use the software with any database so my function accepted a database adapter as an argument.

I could have achieved a similar goal in another way but I would have had to sacrifice separation of concerns slightly. I wanted the ability to substitute any database but also wanted the component to be responsible for the persistence and recovery of its own state as this was within its responsibilities. Also this was the only violation in the entire codebase so I deemed it acceptable. It didn't pose any problems at all in practice.