In truth, this is the opposite in my experiences where a mere mention of the word uttered by white lips gets a frowny face on some of my black friends while others it doesn't bother them at all. You really need to check with them or something at first.
I think I meant to continue that sentence as "drop the word 'nigga' while singing," but my brain was moving faster than I was typing.
But yeah, I agree that a lot of black people get really uncomfortable when a non-black says "nigga" or "nigger." My family, however, simply wasn't raised that way. I think we were always brought up by my mom and grandparents, to not let a single word hold so much power over you and your emotions. If someone is hurling the word "nigger" at you, like it's a knife, it's because they are a small, pathetic, sad person, who should be pitied for his ignorance. My mom grew up in a time when she couldn't drink from the "White's Only" fountain, and had to ride in the back of the bus. She's been accosted and harassed by police, just for being black. And yet, she still taught me and my sisters to not hold that kind of hate and suspicion in our hearts for whites or anybody else.
If some dude is casually dropping "nigga," or singing it in a song, where the obvious intent is not trying to cause hurt, let it go.
I do think "nigger" is an ugly word. I personally don't say it in everyday conversation (or "nigga"), but I'm not going to try and stop people that are clearly not ill-meaning, and are simply comfortable with saying the word, or singing it in a song.
I'm definitely not about to try and make white people feel uncomfortable when they're singing a song. That's just too extreme for me (although, like I said, it can be really funny to see them fumble with the word. It's like you can see the gears in their head going "should I say it, or shouldn't I? Oh shit, the word is coming up now! What do I---NIGGGAA! - my god, what have I done?!" Lol). I love white people...