[scrollaway]

Environments that prefer tabs just use Tan, or otherwise, those environments just didn't use Black at all.

It's not useful to the ecosystem because those projects not actually using Black and unable to make the switch end up in a worse scenario (hence the fork which at least fixes this). Nobody wins, here; at best, you're unaffected.

Again I invite you to look at Prettier which has had as much of an impact (if not more) on the JS ecosystem as Black did on Python, but does support tab indent (and is opinionated regardless).

[wldcordeiro]

The Prettier team has gone on to say they regret giving people several of the configuration options they did though and have a page dedicated to their option philosophy. https://prettier.io/docs/en/option-philosophy.html

[scrollaway]

Yes, you'll find no mention of regretting adding tab support to prettier on that page.

Key quote: --arrow-parens, --jsx-single-quote, --bracket-same-line and --no-bracket-spacing are not the type of options we’re happy to have.

That's because these are entirely stylistic choices. Tab support is a mechanical one. Worth mentioning as well that Prettier supports multiple languages and tab/spaces is a global option, whereas all of these are very language-specific.