Search inside for the 'Game Development Policy', it's separate from the intellectual property commitment. Reasoning is likely from Amazon Games Studios? I think there may be a concern that someone at Amazon might make the next flappy bird or Minecraft and Amazon couldn't capitalize on it.
This is the only rationale I can come up with for the game development policy: AGS hasn't produced anything in 8 years and what they have in the pipeline looks disappointing so...cross your fingers and hope one of your employees makes the next Minecraft.
Heh. I worked in Amazon Games for a bit. It was a very common question. Along with, "What games have they made?" (Breakaway a 'sports brawler', The Grand Tour game a tie in for the show, New World an mmo about being a colonizer, Crucible a third person shooter.)