The person who suggested the same thing in the Homebrew PR was blocked:
> devlinzed - We shouldn't accept a future where spyware is the norm and rely on this environment variable. We know how that turned out with HTTP Do Not Track. As long as spyware is bundled with Homebrew, Homebrew shouldn't be used or recommended or normalized. The solution is for Homebrew to remove its spyware by having explicitly opt-in telemetry only.
> devlinzed - We shouldn't accept a future where spyware is the norm and rely on this environment variable. We know how that turned out with HTTP Do Not Track. As long as spyware is bundled with Homebrew, Homebrew shouldn't be used or recommended or normalized. The solution is for Homebrew to remove its spyware by having explicitly opt-in telemetry only.
> Homebrew blocked devlinzed on Nov 15, 2019