I'm actually not that overly fond of how they made Spike more a standalone character. I really liked how he was a fully believable character who was a servant. Some people are happy just being servants and get satisfaction from seeing someone else succeed. Servant characters like that are very rare and I don't think it's a mindset that should be demonized.

To be clear there is a big difference between a servant and a slave. A slave has no identity of his own and is merely just property of their master. A servant is one who chooses to follow one and get's their own form of satisfaction.