The key thing about the word faggot as an insult is that its used to strip men of their masculinity. It's not necessarily used to put down all homosexuals. People can be fine with homosexuality in general. But if you are straight, and are accused of being homosexual, then that is a different story entirely. This is why gay, faggot, etc will almost always be used in derogatory manners on playgrounds, sports, whatever. And it will always have a defense force of people claiming that they dont mean anything by it, people are too PC etc.
Racial slurs like nigger are slightly different. They put down a whole race of people when used, and also bring people back to a time where they were straight up gettin raped and enslaved. When used as an insult to a member of that race, you are putting down their culture and heritage, and is why it usually is less tolerated. It's less of an insult and more about trashing an entire race. Even if you arent black, people can understand and feel the weight of the word nigger. The use of faggot isn't comparable, IMO. That is, if you agree that its use is to take away masculinity, and not to put down a group of people with that sexual preference
However, its use is also clearly offensive. And clearly people that are gay may hear this word and associate it with troubles of their own. So its use will also not be tolerated in the majority of situations, so there is no real defense for Kobe or anyone that uses it
The key point is to accuse a man of not being a man, being macho or being gay, etc will always be an insult to a straight man. And the word that encompasses this is the word faggot. Unless men suddenly dont care about people telling them they cant get women and like dudes, this will always be a street insult commonly used. It's hard to see this ever changing. Knowing this, I can't get too angry at Kobe, even though the fine was more than appropriate. But then again I'm not gay so really have no idea how some take the word.