Also it will round those numbers silently to 15 digits.

It was a fun time explaining to accounting why their report showed duplicate billing events. Try telling an accountant "Don't use Excel". The solution of course was to prefix a "'" character, making the file useless outside of spreadsheet programs.

I haven't used excel in years, so your rant is a bit misdirected. There's a simple reason why it associates that way - it can open CSV files. Same as notepad associates to things which it's useless for. (but if you don't have anything else, it will work)

I'm just saying that editing CSVs regularly, preserving the formatting, while avoiding the import/export functionality is a very specific use case. It's likely not something excel project managers care about that much either. If the use case is popular, then there's going to be an editor that does it better. If not... tough.