Pre-conditions for the price-demand curve??? There are only two: Monopoly and Duopoly. Internet providers almost always fall under these conditions... that's why they are regulated. Pre-conditions of the price-demand curve for cell phone insurance is a straw-man argument.
You cite Comcast's underhanded deception of their customers as evidence? I fail to see any parallel between Comcast and your situation with your handset.
There are DOZENS of carriers, and in most cases, you don't NEED a carrier to get a replacement handset. My local online classified system has hundreds of devices available, and I could have one in my hot little hand in 30 minutes if I wanted. You have stacked so many fallacies on top of each other that it's difficult for you to see the plainness of the situation: It is not a huge financial burden to self-insure your device... just buy a second one and you can switch devices in a matter of minutes. If you don't want to do that, then buy one on the open market. This solution is probably cheaper than perpetually paying the insurance premium to your carrier. If you buy the insurance package from the phone provider, you are bound by those terms. I currently don't buy insurance on my phone, but I have in the past... and when I did, the provider gave me a pamphlet that stated all the terms of the insurance policy. If you bought an insurance policy for your phone without understanding the terms of coverage and remediation, who's fault is that? If their terms weren't sufficient (can't deliver a replacement fast enough) then go somewhere else.
I'm not going to waste my time looking for a citation, but I'm pretty sure you could find SOME company that would give you a premium insurance plan that would replace your phone as fast as you want, but I imagine the cost of such a policy would be greater than just buying two devices up front.
The best I can do is distill your argument down to this: You are unhappy with the terms of service on your phone replacement plan. You project your own ignorance of the terms of your insurance contract onto others by making this unfounded statement: "most users have no idea when walk out of the store with a new phone, whether the store would give them a loaner phone(sic)." You possibly STILL don't understand that the cellular carrier who sold you the insurance policy, did so as a proxy, and that the company who insures your phone is most likely a 3rd party (citation: every insurance policy I have purchased for a mobile phone was through a 3rd party insurer, even though the transaction took place at the cellular carrier's sales floor). You hold the cellular carrier responsible for your dissatisfaction with an insurance contract to which the cellular carrier is not a party.
Have I summed that up correctly?
My advice to you is this: Be a better consumer. Understand the terms of a contract you enter into before signing or paying, and live by those terms. Understand that mitigating risk does happen at the societal level, but it does so FOR the society, not the individual. I you want to mitigate your individual risk, take action yourself, don't rely on others to mitigate your personal risk. And finally, my most fervent advice to you is this: Improve your situational awareness. When guys in a rental yacht pull up next to your inflatable dinghy and start chatting you up in an attempt to commandeer your bikini clad women... do not be fooled. Keep calm and row on.