First it WAS a big deal. What happened is nothing to sniff at.Sorry, but I think you're contradicting yourself here. First you say 4050 people affected and totaling "only" 90 deaths is not a big deal (which I would agree with) - and now you say the opposite?
If it was commonly agreed that the number of casualties was that low then I really don't get why even the pro-nuclear parties refer to it as the dramatic event that is to be avoided at all costs. Your average earthquake affects and kills more people than that...
Second, the problem is that the anti-nuclear movement [...] in an attempt to use irrational fear to bolster resistance against nuclear
I keep hearing that, but I'm really wondering what are the motivations here?
Yes, there are some environmental nut-jobs who will argue for the sake of it, but those are usually easy to spot. However, on top of that there is also a non-negligible number of more or less credible scientists and first-hand witnesses (doctors, nurses) who question the figure of ~4000 affected. When I see an interview with a nurse on TV who reports about entire villages in the area dying out because they can't make children without birth-defects, then I can't help but ask: Why should she make this up? Who is paying her to tell us lies?
And then, on the other side of the spectrum, we have a multi-billion dollar industry and entire countries depending on the perception that nuke plants are "safe enough".
I'm not claiming to have the definite answer. I just don't understand where people like you are taking their confidence from.