This is a major problem with Scrum. There's always someone telling you you're doing it wrong. If nobody's able to implement your big idea properly, maybe the problem is with the idea or how you're explaining it, not the people trying to do it.
Of course there are, and they are probably paid handsomely for their insight. How is a process that wants to implement individuals and interactions over processes and tools not a parody?
If currently the designer is not working on the same project than the dev, they should not be in the same scrum.
Keep it short, to the point.
Scrum is not a meeting, it's an interactive tiny bite of field report.
Make it anything bigger than that, and you are not doing agile anymore.
It might well mean that you need to bring in the Product Owner to tell them the news so that together you discuss what is delivered to meet the definition of the sprint goal can be adjusted within acceptable boundaries.
If you're wondering why you should accept this definition it's because I recently attended the Scrum Patterns course run by Jim Coplien (the guy who codified the definition of the Daily Scrum and is the co-author of "A Scrum Book" with Jeff Sutherland) and heard it directly from him.
But I understand what you mean: too many people use it to track activity, not as input for the agile loop.