Microsoft Proved CLI Coding Agents Work, Then Pulled the Plug
A Microsoft study of tens of thousands of engineers found CLI AI coding agents drove a 24% lift in merged pull requests over four months, with the effect holding steady rather than fading. Adoption spread through peer networks rather than mandates, and retention tracked with existing coding activity, not tenure or title. One week after the study went public, Microsoft required product teams to drop Claude Code for its own GitHub Copilot CLI. For PMs, this is the strongest evidence yet that developer-driven adoption predicts real productivity, and overriding that signal for platform control is a strategic bet, not a neutral tooling decision.