I don't think we can take Griphook to represent an entire species, imagine if the goblins did that with Lord Voldemort!

Griphook was a kind of extreme Goblin nationalist. Look at his views on goblin ownership, Rowling said in an interview they were an example of a fanatic. Dwarves had their bad bunch as well, apparently all the houses of Dwarves in the far east turned evil.