I hear that it's bliss; is ignorance that good?

Fuming! That's what I am. Fuming! Why are people ignorant pricks? If anyone can earnestly answer that please e-mail me because really I'm clueless here. I'm at work today (which is a chip truck) and a man walks up wearing, in the year 2001 mind you, a shirt which reads (oh I get mad even thinking about it) "Silly F*gg*t, Dix are for Chix!" with a picture of a trix rabbit on it.(I can't say the dorogatory word and seeing my fingers type it onto my computer screen was nearly as awful as hearing my voice spit it out) I was rabid! But the simple fact of the matter was that I was at work and had to let him waltz on by thinking that it was alright that he should be an ignorant asshole. I just clamped my jaw shut and bit my tongue (it bled. If you know me you know I'm probably not joking about that.) When he was gone I went berzerk and the guy I was working with, Jesse, wondered why I hadn't said anything (I'm quite outspoken and normally would have) The fact of the matter is that I was at work. I'm not allowed to yell at paying customers, no matter how wrong I believe them to be.
It is the year 2001. This isn't the 80's where you don't know about the fact that you can't get AIDS from a toilet seat or a hand shake. I thought Degrassi High taught something about homophobia and such (this guy was only maybe 10 years older than my 18, part of the generation that would have grown up watching Degrassi). i hate that with as much progress as I see I still find myself wanting, no needing to fight these people. Whether I get called a lesbian at school (yeah guys it happened) when I'm straight or I get shunned in a classroom because I yelled at the homophobic popular kids, I just can't seem to let it slide. Frankly, I don't see why I should.