Comment by gh02t

Its relevant, however, that the Bluepill and ESP8266 cores for Arduino were originally independent reimplementations by third party hobbyists, not made by Arduino. And Espressif themselves have always developed the ESP32 Arduino library implementation. They weren't completely freeloading off Arduino's work, and Arduino (the company and the ecosystem) heavily benefit from contributors of all sorts. Particularly in the case of Arduino and Espressif, they have been successful together.