People pick on whatever sticks out. Is the developer Russian? Russian insults. Are they of Chinese descent, and he comments?
Sure, but the problem isn't that, but what commonly sticks out and how it's insulted.
Being white usually doesn't stick out. Being non-white does. "Whitey" and "cracker" are almost comical in comparison with other racial slurs.
Being a straight man usually doesn't stick out. If someone still wants to insult a straight man, they usually do it by comparing them to women or to homosexuals.
People use ethnicity according to their prejudices as insults, but you rarely hear "Swedish" as an insult (except maybe on Fox News). So that's very selective. You also see mental illnesses and mental capabilities used as insults. Disabilities as well. Class is also often used ("redneck" isn't just aimed at whites, but poor, uncultured whites).
Some groups are way more targeted than others. If you look at which groups are targeted and which ones are not, you should see a clear pattern.