FWIW, I have music I've measured at 30dB peaks above average. It is multi-channel though, so somewhat less load per speaker than stereo. But still a lot more than 15dB. I also consider 75dB low, I typically listen at 80dB, and some prefer even louder.
That said, I agree in general that people seem overly concerned about SPL. I really do think it's best to know the levels you listen at and the dynamic range you need and just make an informed choice based on that.
Agreed! If you measure and, like yourself, need higher peaks, then you'll know you're getting your money's worth and spending it in the right place!
I think iPhones have an accurate SPL app that is calibrated to their internal microphone. More people should use that and calculate what they need, then get the appropriate speaker.
Heck, someone could probably make a cook app that used the rangefinder on the iPhone and you could point it at the speakers from your TV and it would tell you distance and SPL.
Then you could have the user move within one meter so the speaker didn't have to work as hard, and then start increasing the amount of distortion.
From there you could combine it with data from here so a person would get a speaker that played loud enough, with roughly low enough distortion they couldn't hear it as tested with the app. Then just add Amazon links to the appropriate speakers and that could help fund it.