The argument would go something like this:
MS were contractually obliged to assist OpenAI in their mission. OpenAI fired Altman for what they say is hindering their mission. If MS now hires Altman and gives him the tools he needs, MS is positioning itself as an opponent to OpenAI and its mission.
They were positioned that way by the OpenAI board, which has effectively committed corporate suicide and won’t be around much longer.
the bottleneck right now is mostly compute I think, and openai does not have the resources or expertise to allieviate that bottleneck on a timescale that can save them.