I think the issue I have is that they all talk.
Don't mind some talking. But some of the magic is missing if they all talk. So have some talk yet others show.
Larian is about making systems that allow for silly/fun, even exploitative gameplay - and speaking to a plethora of animals (and dead) is part of that. I believe they like to refer to that as promoting "player agency" -- in which realism, immersion, balance and other concerns are of secondary importance.
You have a similar issue with "fire dipping" weapons. Instead of accepting the D&D framework which allows for many ways to achieve a similar effect (ie. cantrips, spells, expandable resources), Larian had to make it an universally accessible single system and thus make an already dauntingly complex system needlessly more complex. Same thing with barrelmancy, show/throw or pickpocketing, really.
Their thinking is that if you don't like a mechanic, just don't use it. Problem is when these systems become so prominent, not using these systems feels like losing out on a lot of content (resources that could be put to arguably better use) or even consciously nerfing yourself (which is opposed to the fundamentals of RPGs). That said, talk to animals/dead is one case where I feel this design philosophy really shines and does not infringe too much on realism and immersion.
