Creativity
By someone creative

What I love/hate about creativity is that to some extent everyone has a creative muscle whether its a practical ability or mental one. The upside/downside is that creative muscle gets flexed every time an opinion is asked on a design, hence "head against the wall syndrome" suffered by every designer at least once a month.

If you pay an engineer to make your car run cleaner and he says you need an oil filter changed you don't say "Hmmm I don't know why, but I don't like that idea." Doesn't happen. You appreciate their learning and experience and you TRUST their assessment. So the question is do you have the trust of your client to take your recommendations over their own opinion? And, is the trust issue with you specifically or is it with the industry you represent (slightly bigger question)?

Objections to a design are either emotional or practical, but both are really requests for more information from you. This is your opportunity to explain your choices more in depth with your client. It is a great stage of the process as it is at this stage the client really begins to understand who you are, what you represent, and what they are getting from you. Its at this stage you start to develop the trust that makes it easier to say "Nope white text on a pink background is not going to help you sell more cars.." and them more receptive to your opinion.

If all else fails do it in blue... everyone likes blue ; )