You actually wrote

I’ve been doing it for 2 decades, still don’t get it. So maybe you can enlighten me what IT has to do with naming stuff in code?

You capitalized “it”, so I thought you meant IT, as in Information Technology, as in device management and shit.

Anyways, idk if I can offer any insight that you haven’t read already. But naming conventions are a small detail that people get really passionate about. Additionally, when people don’t follow the agreed upon naming convention for the project, then the pull request ends up turning into a big argument about renaming shit, rather than an actual code review. This will sometimes spark an even bigger conversation in slack, which can turn into a meeting, and waste a lot of time.

Its usually junior engineers that don’t follow it, because they’re using all of their mental faculties to solve the problems, and then senior engineers see the deviation from convention and call it out. If you don’t have a team style guide, then that call-out can turn into a big ol argument between the senior engineers about different philosophies. It’s annoying, but it’s less annoying than working in a project with no agreed-upon naming convention.