I don't like it when non-git tools do that by default. I'm sure it's nice for some people, so make it an option that could be enabled. But to have that behavior by default feels far too opinionated for me.

Generated files. If you're searching for every place something shows up so you can change it, it's annoying to have to filter out the stuff that'll get updated automatically (and will mess up timestamps if you update manually.)

Also, backup files. The fewer irrelevant results, the more useful a tool is.

To answer your question directly: If you're grepping through source code, you generally do not care about caches, backups, personal workspace configs, node_modules, "compiled" output (JS projects generally "compile" to JS and if you're looking for something in source files, you probably do not care about the bundles you're outputting, just the source), etc. You generally care about your source code, which is the stuff that's not getting added to .gitignore.

Since we're talking about an open source project, try to keep some empathy for developers that are solving their own problems first and not trying to solve everybody's problems. It's a configurable option, anyway.

Exactly. And if you wanted a Git aware tool, you could just run 'git ls-files'.