Well, if HGTV is anything to go on, most clients don't actually HAVE a vision and are delighted to have someone give them one! And those that do have a vision will be looking for a decorator who understands & can support what they want to do -- so I guess there'd be some self-selecting going on on both sides.

And you could probably get some training that would help you suss out how to handle this.

I think you'd be really good at it.