"So that the site will work" is no less insulting to their intelligence, at the end of the day. They know exactly why it isn't working, and if they want to see it work they're welcome to fix it.
But asking for a custom-crafted marketing pitch job aimed at converting a small and pathologically hostile market of noscripters is completely outside the realm of feasibility, here.
You're the one who stands to profit from the interaction. You do the legwork.