I’ve had a few projects recently where an existing site need a lot of help in a lot of areas: poorly organized, ineffective design, hardware or programming problems, inconsistent integration of various services, etc.
Problem is, design is visual, and clients get that. So they know they want a new design. The other things are harder to grasp. When told that they ought to step back, review their priorities, upgrade their hardware, reorganize the site, and then put a new design together, there’s a disconnect. “Okay, you’re telling me all that other stuff is important, so fine: when can I see the new design?”
Or, worse yet: “Right, we’ll do all that other stuff later — we want the new design now.”
You end up with linoleum design — covering all the problems with shiny new buttons. Perhaps you’ll fix some things, but the underlying problems will still be there. And if those problems are slowing sales or otherwise reducing the value of the site, the shiny buttons will not fix the problem.