Because people that actually profit from piracy are conveniently based on countries that have a bad history of cooperating with US Courts, often behind fake names & companies, and otherwise legally insulated from any actual repercussions for their actions.
If/When their app is taken down by google/apple, they already made their money, relaunch the same app, reskinned, under a different name and different company, and keep profitting. Or just take what they were able to make off with and call it a day. It's a win/win for them.