Scarcity of Patron Bond
Yes, every elf knows the spell Patron bond, but not every wizard does. The elves' knowledge of this spell signifies how familiar they are, as a race, with selling themselves out for supernatural power. Human wizards, on the other hand, possess no natural aptitude in this regard and must actually learn the Patron bond spell to create the bond, have someone with an existing bond to the desired patron cast the spell for them or find some other extraordinary way to enter into the bond contract with the patron. I think it should be fairly safe to assume that the great wizards of the world likely serve one or more patrons (see below) and probably know Patron bond; it wouldn't be unseemly for them to require apprentices to enter into a supernatural bond with a preferred patron, would it? Perfoming Patron bonds for others is a great way for adepts to improve their relationship with an existing patron, and so while the spell may be somewhat scarce, opportunities to have it cast on one's behalf should be present, even if the bargain may not be exactly what you're looking for.
Sorcerers are not clerics, are not clerics devoted slavishly to one being. No, sorcerers do not place themselves below their patrons like clerics make themselves subservient to gods; instead, they are willing to create a "Dutch book" of contracts and compacts with otherworldly powers in order to assure themselves the greatest possible personal magical might. Yes, a wizard or elf may favor one particular patron, but rarely does he make deals with one supernatural to the exclusion of all others. It is, of course, incumbent upon the sorcerer to make good on the terms of each of his supernatural pacts, which can be made much more difficult when the terms of these pacts come into conflict with one another; when currying favor with warring patrons, the sorcerer may find himself as the middle against which both sides are played.
Next time, we'll look into some of the mechanics of the patron bond and how we DCC Judges have a lot of flexibility to use them to our advantage.