The reason that you see better through the pinhole is that you are reducing the aberrations/distortions of the light. You cannot retrain yourself to look through a narrower area, unless you intend to walk around squinting your whole life. The eye already has an area of most sensitive vision centrally. It's called the fovea.
It would be an extreme concept if the extraocular muscles affected the focus of the eye because they are attached to the eye in the form of a lever, and do not have compression as a function. When they contract or are tensed, they turn the eye, not compress it. So if there was some built-up "stress" in them, your eyes would just be misaligned. This is not higher learning theory, it's just basic anatomy. This is like denying that the biceps contract when you flex your arm. Is it possible that all the anatomists are wrong? Possible, but not likely.
Many people who wear glasses don't have any change in prescription for 10 years; some change in 6 months. We are starting to repeat many points found earlier in this thread. Yes, the glasses are a prosthetic. They don't claim to have healing properties. Conversely, I don't see how exercises that require "maintenance" are not a crutch.
Furthermore, there's also no logical argument in how glasses make your eyes worse. What are the glasses impeding you from using, exactly?
Already explained that pressing on your eyes and seeing focus changes is exactly like orthokeratology, the cornea is merely being temporarily deformed.

Glasses are about as unnatural as having braces on your teeth. They're for people who want to see 20/20, just as some people want to have perfectly straight teeth. It's natural for people not to be perfect, just as some people are fat, ugly, uncoordinated, etc.