A company in the US is designing a proper electronic ignition timing device that will be able to be fitted to most of the higher powered piston engines...IO520/550/TIO540 etc...you get the picture.
When that comes on the market it will mean that engines that currently require TEL to control detonation while still producing sufficient power will be able to swap to unleaded super 'mogas'.
TEL is VERY bad stuff and the limitations on 100LL manufacture and transport are as you suggest...somewhat stupifying...but to just stop manufacturing it until an option exists and grounding 10 of thousands of piper, cessnas, beechcrafts, and the various piston flingwings is not worth considering.
Chuck.