While I agree some people here go overboard with hearing protection, this increase in noise sensitivity after wearing hearing protection is only a temporary one. It is not the same thing as the brain turning up the auditory gain when there is a permanent loss in hearing.
With regards to noise exposure that isn't dangerous to most people, I developed a new tone in my right ear after a noise exposure at work back in October. I spent about half an hour in an area that I would estimate was at most 90db, but it was probably less than that. I had deeply inserted large foam earplugs at the time, but apparently that was not enough protection. That tone has not gone away, and it's not some psychosomatic spike. Spikes in volume are somewhat relative in my opinion, they can be attributed to stress, lack of sleep, noise exposure, diet, etc., but completely new tones that do not go away are something different.
What is safe for you may not be safe for me. And the fact is there has been no good study done assessing the vulnerability of already damaged auditory systems. The gold standard for dangerous noise levels is based on old data from OSHA where they looked for permanent threshold shifts of 10db or more at 2000, 3000, or 4000 Hz. As we know now, you can have fairly significant auditory damage without having a permanent threshold shift in those three ranges. There is also a lot of industry push-back when OSHA tries to make safety guidelines more strict (I haven't seen this with noise levels, but I have seen it with chemical safety guidelines). Moreover, it's very likely that some people are more genetically predisposed to hearing damage than others.
What I'm getting at here is I agree with you that some people really do go overboard with hearing protection, and obsessing about noise is not healthy, but it irritates me when people adopt this attitude of "well it works for me therefore it must work for you" or "it's safe for me therefore it's safe for you". No one can say that.