I’d say it’s still very important for internal consistency reasons. On top of it being a very good idea to have a story that is internally congruent, if the showrunners themselves don’t care about the show, why should I?

While I personally don’t mind much if they make a mistake here or there, or a few bits of dialog don’t line up, it still makes for a better story and overall show. If they’re not even trying because, “lol it’s fantasy anything can happen”, then fuck ‘em. Trash people that shouldn’t be involved in creative works.