NT was and continues to be multi-platform. That doesn't mean every platform was or would have been profitable. x86 became 'good enough' to run your mail or web

NT was and continues to be multi-platform. That doesn't mean every platform was or would have been profitable. x86 became 'good enough' to run your mail or web server, it doomed other architectures (and commonly OSes) as the cost of x86 was vastly lower than the Alphas, PowerPCs, and so on.