The problems commonly experienced are simple to understand because in many cases you have an agency with a small team, or one person who does all the graphic design, this one size fits all from one person never works. Yes if they get the right work, with the right brief then they can produce and meet expectations. However the moment they are bored by a job, or they do not understand the brand or are being asked to do something they do not believe in then you will encounter problems.
The trick is finding the right creative person for your job, sometimes it could be that slightly less experienced person who follows the input and meets client expectations, other times it will be that super experience creative who can bring something to the table that is needed, that real experienced creative flair. You can keep trying to push a square peg in a round hole but let me tell you it takes up far more time than it is worth and it is also not good for relationships!
I love the fact that part of my jobs with clients is that I fully understand what is required and then I go off and find the right people for the job, and guess what if they do not deliver the job moves on from them, simples.