how many mac users are actually interested in gaming? 5%, 10%, maybe 20%?
Probably worse than that. How many mac users that use mac exclusively are interested in gaming? 5% would be high in my view. Those that have a specific desire to game have a PC or also have a mac.
Moving forward, if AAA games came to mac the cost is going to be high. That is the cost of a mac capable of gaming at that level. How many with gaming specifically in mind are going to spend the required $3k+ that will be needed in the future for an Apple device that could cope with AAA? Not that many. They will opt for a standard Apple device and a PC which likely cost less combined.