He (Linus Torvalds) made Linux as a hobby during his time in college/university to teach him about operating system design. Because it was the part of the operating system called the kernel that the GNU project didn't have yet (more on this in a moment), it became very popular.
Richard Stallman created the GNU project because he believed that every person should have the right to study and share the software that runs on their computer.
There is nothing specifically anti-corporate in either of their motivations.