I'm guessing you must be on older hardware, because I haven't noticed any degradation in perfomance, stablity or battery life on iPhone 5.

The other thing is that piracy does NOT negatively effect the industry, at least not to a significant degree. It's an excuse the game companies come up with to explain declining sales of a tired franchise that they release the same exact game with next to no changes year after year. (I'm looking at you EA)