The problem is that both Apple and Wintel were fighting for consumer customers; people that were proficient enough to word process, email, and browse, but not proficient enough to understand chip architecture. They just see a spec and assume higher is better. If you have to start from a position of arguing that the your opponent's advantage is a myth, you're already at least a step behind.

Moreover, the enterprise market had lost that war already. Who cares if PowerPC was really faster? Intel was a cheaper chip that did the job. Everyone in my customer service, accounting, HR, etc department can have a PC for much cheaper than Apple.