The approach assumes that it knows everything there is to know about off switches in general, or what its creators know about off switches.

If the AI can guess that its creators would install an off switch, it will attempt to work around as many possible classes of off switches as possible, and depending on how much of off-switch space it can outsmart simultaneously, whichever approach the creators chose might be useless.

Such an AI desperately needs more FAI mechanisms behind it, it desperately needing an off switch assumes that off switches help.