Looking at the list, it doesn’t surprise me.
NBA, Madden, FIFA, and NHL attract the same sports lovers every year.
MGS V was very anticipated by many, many people.
Destiny has a ton of players; no surprise TTK got a lot of players back. It supposedly came with quite a bit of improvements to the base game, but I don’t have Destiny so I can’t say for sure.
Super Mario Maker might be one of the best games the Wii U had in a while. I never played it, but I haven’t seen much negativity about it, save for some bad courses people made.
Disney Infinity and Minecraft? Little kids and the parents that let them play.
And Mad Max was probably a huge boom because of the movie.
Forza, and racing games in general, are rather niche. You have to like racing to buy a racing game. I couldn’t care less about sports, EA couldn’t pay me to play two hours of FIFA or Madden. That said, there’s millions who keep track of all scores and all games.
Physical retail only might have something to do with it too. People like disks, sure, but the bundles were digital only. I bought digital. Everyone who got the Deluxe or Ultimate Edition bought digital. To get an accurate scope of how many people played FM6, look at Lime Rock (don’t know what ribbon though, Full?) C-Class Leaderboards.
Edit: Xbox exclusivity doesn’t help it’s case either. Not to say sales would skyrocket if it were for PS4 and PC too, but they would increase.