Emma, I don't disagree with you - the forum is indeed an extremely valuable resource for the company (and for its participants) - replacing its function with paid staff would cost a fortune. But there's no way any business would do that (it's not their main business, and frankly why should they spend all that money when they can get it done by volunteers?).
To be clear, I have no doubt they do value the efforts that everyone puts in here. They also do spend some money on its maintenance (multiple employees work on it behind the scenes; and it's software so like all software, it requires ongoing updates, tweaks, backups, and regular maintenance). But I'm also quite sure they want to keep the costs associated with the forum controlled. No doubt they keep a list of potential feature enhancements (and bug fixes) somewhere, all those items are prioritized (and each probably has some wild guess cost estimate) and periodically they review that list and decide which (if any) of the items are worth doing. They do make improvements and changes, just not a lot of obvious ones we notice.
So yes, they do make ongoing financial investments in the forum. But adding new features (like the option to customize date formatting) all get added to that big "to do list" and have to compete against other items, with limited resources. I'm sure they don't mind getting requests for improvements. But this is one I'd guess is not likely to bubble to the top of the list.
Again, just an observer here making guesses.