People buy it. People then buy the skins. I play the free to play one sometimes and nearly every single person I kill has a $30+ skin and weapons. It's saddening.
One of the funniest things with cod too now, is that people always used to say it was the same game every year, but it is actually the same game every year now, with progress and weapons carrying over.
Gone are the days of a one time purchase and a solid game. (Well in the AAA space anyway)