Except this basic financial reasoning called Return on Investment. AAA games run in the hundred to hundreds of millions in development, so let's be 'very optimistic' and say the Mac port 'only' took 1 year, and we'll go light on the cost, so 'only' $25 million for break even. The goal of businesses isn't 'break even' AND there are also addition costs to support each platform and it's user base on top of that, let's assume for simplicity double the dev cost to cover support, maintenance, bug fixes for MacOS over the life of the game. (Example #, each type of software has unique support costs to it, but it's probably at least 40% of the dev cost..). Now we're at $50M. Unless they could guarantee net revenue of somewhere around 3-4x that # or more - nope, it's not viable for most businesses to pursue.
So yeah, 'lazy,' or just math and business basics.