You do not understand the point that IO540 makes. He is referring to the fact that the flight is the responsibility of the pilot, not the airport owner. hence, the pilot should be responsible for, for example, not flying into cranes that are not in fact anywhere near the airport.
Of course, but it's not the pilot's responsibility alone. If there is a hazard then the airport operator may have a responsibility (and liability) if a pilot has an accident.
The argument that a pilot has ultimate responsibility for safety is not a reason for disregarding conditions that an airport operator imposes on use of the airport, unless the safety of the flight is jeopardised. Phoning for PPR hardly puts a flight in danger!
I think the requirement for PPR is a bit over-done, and if I change my mind in the air then I might call on spec and see if they'll take PPR over the radio. But if I do know where I'm headed, and they want PPR by phone, then I phone. Why on earth not do so?