I want to sue Bob Dylan for something.
My initial response is this: some people are way too sensitive, but I can see the point in drawing stupid comments to people's attention. I can't sense Nazi blood -- but if someone says they hate fill in any group I'm pretty sure I don't want to be in that conversation or in a conversation with anyone who makes judgements about individuals based on membership in any group.
Depends what you mean by "membership". Doesn't membership typically imply willful joining? While I am a member of the white race, I wouldn't equate that with membership in the sense that one can be a member of, say, a country club. Membership in a group (by choice) is a proxy for one's beliefs, given that many organizations have creeds, mission statements, rules, etc. It's OK to judge others by their choices (after all, what else can we judge others by?). What it's not OK to do is to judge others by the circumstances into which they are born. (Maybe I'm just having fun needling you about word choice, but you seem to like language, so why not?)
Needle away. I will be your haystack. (Does that sound naughty? Sorry.) You are right to differentiate between groups by choice and groups by birth. As I was writing the comment above, I was thinking about generalizations such as "Those tea partiers are f'ing stupid." I just went searching the web to see how I could join the tea party in Succasunna NJ, for example. I discovered a lot of tea parties and they have meetups -- just like Hubskiphiles -- (except more guns). Some groups really try to put the Party in tea party. All the local orgs that I saw had mission statements and these statements were not all the same. There's a lot of local tea parties, but I doubt everyone holds exactly the same set of beliefs or has the same education or are motivated in the same way by the same fear and the same ignorance (generalizations noted) or by the same love of their country. You are right that people join organizations mostly voluntarily, but also through coercion or pressure or brain-washing or family unity or to follow a loved one -- and they also quit those organizations. People go on marches sometimes without thinking through the implications of the group they are supporting. Revolutions can be fun and people like groups. So, yes, I would hold by my statement that generalizations about individuals based on their voluntary or involuntary membership in a group tend to be problematic.
Also -- I don't see anything wrong with trashing Nazis as a group, but Croats are slightly different in that, you know, it was the government that perpetrated the genocide and the average peasant didn't have a thing to do with it. This is all especially ironic because of course the Nazis were running the Croatian government at that point anyway. With all of that said, Dylan was using language to make a point and I generally take the "people are sensitive about silly things" side on this sort of thing.