Since I don't know you personally, I can't say for sure, but I'd guess that you're engaging in self deception. I doubt anyone ever said to you, "I don't care at all if there's a tip, I think all customers are equal, and some of the people that don't tip are great customers". It seems more likely that a buddy said, "not that big a deal, I don't get mad or anything" and you concluded that it's not a problem. Everyone wants to believe in their own inherent goodness.
Right, like I said, it's your call to not care. Just don't delude yourself into believing that servers like you.