Short Answer – Because you cannot get the software to meet your needs any other way.
This decision was not made lightly, but was the result of long term brewing difference of opinion and direction between the originator of FreeEMS, and a subset of the core members and would-be developers. The core author of the FreeEMS ECU firmware, albeit talented and technically adept, is not a team player, and through various ways interacted in a consistently manipulative, negative and demeaning/demanding ways with the core development community. This had the chilling effect of basically turning away multiple would-be developers from the project over time, some of whom, were seasoned software engineers. We’ve had multiple instances of people submitting promising ECU firmware code, only to have it outright rejected with poor justification and ad-hominem attacks. These sort of issues naturally are EXTREMELY destructive to a project and many of us became disenfranchised with the leadership of the project. It was thought that a clean fork under a new name breaking away from the original developer of FreeEMS might be able to foster a more collaborative and fruitful group with a higher chance of long term success. We think the infusion of fresh ideas and OPEN collaboration will result in a much better chances for long term success.