So you're only counting people who already have somewhat capable gaming PCs. But those laptops can't run games like Forza 7, Forza Horizon 3, Crackdown 3, State of decay 2, Gears 4 even on medium settings. And like I said before, MS is prolly okay with that and still makes money through Windows store.
And there is also a crowd who buys consoles for only for your annual CoD, BF, Madden, NBA and FIFA, as evident by some of those games outselling the 'awesome exclusives' on PS4 alone