Demotivating to whom? I imagine the intent is to avoid creating an impression that anyone has the power to make their pet issue priority #1 for the dev team just by throwing enough money at it.
"Learn how you can earn paid grants improving Pengwin."
"Your proposal will be promptly evaluated" ... "Your work sample and GitHub history will be evaluated to determine if you have the technical competancy to implement the proposed change and deliver timely." "If approved, you will recieve a simple agreement covering the scope of the work you will be doing which you must acknowledge and return and then you may commence work."