I have a 40, and I agree with your statements. After Tesla dropped the upgrade price for 60/75 owners, I inquired again about unlocking my 40... and was quoted the same $11k.
I think Tesla should reduce the unlock price. However I don't think they will, simply because they have no interest in even considering it. There isn't a practical benefit for them. We've been forgotten; they have other things to focus on.
Even if they did discount the price, what would 40 owners be willing to pay? I definitely will never pay $11k. I don't think I'd even do it at $5k... maybe $3k?
I've come to accept and somewhat relish in the fact that I own one of the most rare Tesla's out there (more rare than the Signatures). It's something a bit special... it has a story... do I want to make it just another average old "60"?
btw - Tesla will also allow you to enable "Fast Charging" and buy the CHAdeMO adapter without unlocking the battery for ~$2500. Still no SuperCharging, however it's at least an option.
My S40 range also dropped from 140 to 125. However, I never really got 140 miles of real range out of it... I think 125 is just a more accurate estimate. Maybe that's due to it carrying around 20kwh of dead weight?