People are making it sound like this is a huge company with a product and not a grouping of curious people with a couple hours of free time on a Sunday.
Most likely they never thought about it, then it broke, then it was not impactful enough to fix on their free time compared to other stuff.
https://github.com/neovim/neovim/pull/13973#issuecomment-789...
If it's really just a toy with no expectation of not unexpectedly destroying user data then they ought to make that more clear.