The .editorconfig specifies things like tabs vs spaces and the indent size. Everybody needs to use the same settings to avoid messing up the formatting every time they edit a file. Therefore, .editorconfig gets checked in so that everybody gets the same settings.
To me the scourge is tool config files being in the repo at all.
Ok I’ll make an exception for .gitignore or something that enforces house style or formatting conventions to make things proper for check in.
But an editor config? That’s so user-specific and shouldn’t affect (or should I say “infect”) the source code.