Not totally sure how to respond to this, as you don't seem to have actually read my comment, but here goes
> "you are missing out on unimpeded hearing"
As I said, my plugged hearing is now as good as my formerly unplugged hearing. The only thing I'm "missing" is a couple kHz at the very top, above about 18kHz. I don't miss that, really. And if I want super-human hearing (like when I'm reviewing audio equipment), guess what? I just take them out!
"fear of hearing loss"
I started because of actual hearing loss, due entirely to "everyday" events; occasional concerts (jazz mostly), some woodworking and yardwork, screaming kids, etc. I developed a bit of notching at treble frequencies and I lost a lost of top end. According to a hearing test last year, I have managed to reverse most of this. I'd bet money you've incurred at least the same amount of loss.
> "Normal level sounds don’t degrade hearing as far as I know..."
It entirely depends on your definition of "normal". The NIOSH limit for exposure to 85 dB is 8 hours. 85 dB is not that loud; it's driving in traffic with the window down. Drive a crappy car in the city with the windows all the way down and it's closer to 100. Ask a farmer or trucker how much of that "normal" level is safe.
> "not based on science."
Cute. Since I'm sure you're up to date on this stuff, can you tell me why the NIOSH exposure thresholds don't use equal loudness curves to account for frequency? I'll give you a shiny science star if you figure it out.
> "and loud sounds aren’t that common..."
Um... yeah, actually they are.
> "You could expose yourself to 8 hours a day of a lawnmower at 90 dB and 90% of the population would be fine."
Great, you've convinced me! A mere 10% chance of hearing loss after a half day of moderate sound levels is totally reason enough to abandon a practice that allowed me to recover a hearing level almost as good as my 8-year-old kid's.
Seriously though, if the only data you're reading comes from occupational safety guidelines, you're going to fuck up your hearing eventually. NIOSH is a blunt instrument, meant to make it easier for industry to minimize liability for worker disability. But there's a world of benefit outside of occupation safety regs. I like hearing better. Pretty simple. Plus, there's good evidence that sub-acute noise-induced hearing loss is a significant component of age-related hearing loss. Remember that when you're eighty and pissed off that you've misplaced your hearing aids.