> I feel it's Orwellian, or Stalin-esq to have us being paid off to snitch on each other.

Sure, but it's a different kind of dystopia to have commercial vehicles idling and fouling the air outside of normal driving. As described where you have to capture 3 minutes of idling (1 minute near schools) and assuming most people take a while to notice, rather than starting the timer immediately when the vehicle stops, it seems like a reasonable way to enhance compliance.

Idling while parked may not be a large contribution to total emissions, but it's harder to justify than idling in normal operation, and easier to enforce against, so there you go. Sometimes refrigerated transport more or less needs to idle to keep the contents at temperature, not sure if there's exceptions for that or if they just need to retrofit with more insulation or batteries to run the compressor or etc in order to comply.

Idling at lights probably gets reduced by auto start/stop in new vehicles as well as congestion charges reducing traffic and probably dwell time at lights. Auto start/stop isn't a universally loved thing; it makes some cars really frustrating to use, but when done well, it seems like a reasonable tradeoff to reduce unneccesary emissions.