Absence of Comms
To EMIT and others who think that an absence of comms for 1+40 (or even 0+40) is no big deal (as in "let's not make an elephant out of a mosquito") I have news for you. From the ATC point of view (especially in busy, crowded airspace) it's a big deal.
I would suggest you visit such an ACC; sit, watch and listen for a bit. Then ponder what would be going on in terms of re-routing and re-clearing of altitudes to accomodate the a/c that is "not participating". ATC is much more of a dynamic endeavor than many realise (even high-time pilots); so the actions that must be taken significantly increase the workload, the inconvenience to other traffic, and indeed the stress level as -- despite ICAO and JAR -- one is never quite sure what the aircraft may do, and so allowance must be made for that.
Been there (at the ATC position) too many times.
Grizz