I think no one's arguing that, if your project calls for it, you could just write javascript and commit it to a repository and be done about it. All these tool

I think no one's arguing that, if your project calls for it, you could just write javascript and commit it to a repository and be done about it. All these tools just add guarantees to the quality of code in a codebase so that it's easier for a lot of people to work on the same app. Is it slower? Sure. Is it worth it to keep from deploying bugs? Also probably sure. As a side note, I'd argue that running tests should probably not block you from committing code, but it should keep you from deploying code. I work at a company where our hooks are (usually) pretty fast, but keep you from having to rerun a much larger test suite.