You need to stop propagating your personal beliefs and biases as some kind of fact. Passive bi-amping is bi-amping, not bi-wiring, plain and simple. Your assertion that there is only one power supply in a receiver just shows that you're not very up to date on modern receiver design which employs multiple independent power amps with different transformers and capacitor banks inside the single receiver.
If it were bi-wiring, you could leave the shorting posts in place without issue because the power supply was the same. Passively bi-amp a speaker and try leaving the shorting straps in... obviously, they'll zap each other dead because they're different power supplies and will short each other out.