With the N word, you're perpetuating a hurtful stereotype. With 'hey you guys', you're perpetuating a hurtful stereotype. The roots of both stereotypes are a form of supremacism where one group asserts its dominance on the other. The former is about racial dominance, the latter is about gender dominance. It's basically saying one group is more important than all the others, or one is inferior. That has real world effects and does really bother people.

Maybe only one of them bothers you. That doesn't mean only one of them is valid. Logical deduction shows that they are both discrimination. It's up to you to decide what kind of discrimination you care about.