It's just visually jarring. Do you consider your use of spaces after commas and periods and capitalizing the first word in a sentence "pedantry"? To me it's at the same level.
This is a style issue. Not at all on the same level. The ISO standard defines a space, but many, many style guides suggest otherwise. E.g. Very often you will find advice to omit space for one-letter abbreviations (i.e. '100g' not '100 g') — I believe this specific one is in the Chicago Manual of Style.
Keep being you. We all have our weird things that bother us. Apparently the spaces issue is centuries old and used a minority of the time, so you've just got a lot of convincing to do. Maybe you can multiply your effects by writing bots that, for instance, submit github pull requests. Good luck!