Mmmmm, you mean like every other business that exists or ever will exist? Every company borrows and innovates based upon the works of others.
Is every car company a parasite because it uses the seat belt first invented by George Cayley? Are all modern computers (Max, Linux, Windows) parasites because they use a mouse (invented in 1963, with a ball in 1968, shipped with computers in 1970) and windows on a desktop (hint implemented before the first Apple Mac).
By your arguements Apple is feeding parasitically off of Microsoft with the iPad as touch tablets with Windows OS's predate the iPad by quite a few years and hell possibly even touch tablet efforts by others before that. And Linux has been parasitically feeding off of Mac, Windows, UNIX, BSD, and any other operating system ever made. And Android is feeding parasitically off of a variety of efforts by other companies, ad nauseum.
If companies weren't allowed to incorporate ideas from past products and innovate upon them, we'd still be stuck in the stone ages since noone would have been allowed to use the concept of a wheel to produce better products.
And all those beer companies. How dare they each make the same basic beverage using the same basic ingredients. OMG, and don't even get started on restaurants or toys or books or planes or...hell anything made in the history of the world.
Regards,
SB