Originally Posted by
Segev
That's an argument that makes planar binding literally never work. Planar binding cannot make them agree to "unreasonable demands." If the very casting of planar binding - which "[yanks] someone out of their home" so you can "[demand] they do whatever you say under pain of" some threat (death, imprisonment, pain, etc.) makes the request itself unreasonable, then planar binding literally never works to get you the service it spends a lot of text discussing the negotiation of.
A request can be reasonable even if the means used to make it are not. "Please prepare a delicious lunch for me to eat," is a reasonable request (especially on the scale of services planar binding is usually used to secure). You can just ask somebody you meet to do this, or you could kidnap them and drag them, blindfolded, to your secret underground kitchen and then make that request. The reasonableness of the request itself is unchanged.
In fact, the incentive to agree to it has increased: you've proven that you're willing and able to put this person under your power and imprison them in a location of your choosing; the fact that you're clearly not letting them go until they make for you that tasty meal is going to make the reasonableness of the request compared to the unreasonableness of the alternative strongly encourage them to just comply so they can go the heck home.