Personally, I blame Mephisto so I used him as the header image for the article. This is becoming more and more relevant for PC players as well, as many have been finding the controller-based gameplay to be pretty great and are switching over, so maybe give it a try (while slowly pressing buttons in the menus). This is a pretty serious issue and hopefully we'll get some sort of delete confirmation windows added soon, but until then be VERY careful in the character menu if you're playing with a controller.
However, accidental deletion of characters has also affected some keyboard and mouse players, as it's just too easy to instantly delete them, although not quite as much as on controllers:
The primary concern is very much a controller-specific issue, as the required button presses are on the most used buttons (X and A on Xbox controllers) and we've now had several players reporting having deleted their high level characters because of it. Here's another warning for anyone playing with a controller (and even on mouse and keyboard to a lesser extent), whether it's on console or on PC, as deleting your character is entirely too easy and can happen to anyone!