(I hear similar complaints from friends who are professors. Professors nowadays seem to have become professional fundraisers who do a little research on the side. It may be time to fix that.) Now there's a startup idea!
In an ideal world, you could sell the service of helping professors to prepare their research proposals. You could also keep an eye out for grants which the professors might be interested in, and generally handle the money side of things for professors who would rather be worrying about something else.
However, I don't think this would work, because the professors have no way to pay you. As far as I know, no funding agency will fund you for the cost of contracting someone to prepare your grants for you. And they probably won't want to do it out of their own pocket, because; heck, this kind of service will be really expensive (and professors hate funding their research out of their salaries anyway).
But if you've got another business model, I'm all ears.