These are the only ones I've spotted from a quick browse through the Store, I assume there is more. But how on Earth do companies get away with stuff like this? I can understand it on mobile app stores, but are there no checks before these games are put on the PS Store?
Are you knew to this planet? For as long as people have been creating things, people have been making copy's.
As long as they have coded the game from ground up and haven't taken anything from the originals games besides concept, then it's legally fine, minecrafts a knockoff, portals a knock off (except they actually brought the thing they knocked off).
Then you go look at the list of B-movies being released. Every major film will have at least 2 knock-off versions.
No one's making you pay for it, so just ignore it, and if it bothers the original creator, then they can deal with it, but most the time it's not worth caring about for them.
I‘m not saying I know why, but I wonder if it’s like crap movies going straight to rental. In this case, Sony (the rental place in this analogy) gets to look like it has so many options, and also a cut of each sale. So screw it, any new thing for sale is a good thing. Even if it sucks, you (the buyer) picked it out.