The last thing you want to hear when your target clients read your brochure copy is that "you do not know what you are talking about."
No matter how great your design is, if your copy reads like the person who wrote has a lack of understating on the subject, then the time and energy you put towards printing brochures will be wasted. Laziness is often the cause of marketing copy that is insufficient to describe what you really do. If the writer did not do any research to understand both the technicalities of the product, as well as the needs and interests of your target market, the result would only disappoint and convince them that your message does not have any value at all.
Another problem with writing marketing copy is that the one writing it usually seeks to be clever - more than what is really needed. Being creative is a good thing for any marketing message. However, having to do it too much often turns off rather than engage the target readers. How does it benefit you to tell a joke if the reader does not get it? Then there is the problem where the writer assumes that the reader knows what he's talking about. Technical people often make this mistake with their marketing copy. These people usually have a solid understanding of their product. Hence, they can very well describe their product fully. However, they also take it for granted that the reader speaks the same jargon, has the same level of understanding and interest, and the same technical expertise. This then leads to your printing output not getting the message across the way you want it to.
The key then is to plan well and carefully study the product or service that you have. Be able to write copy that your customers will surely appreciate. Your marketing copy should then be about having a balance between the technical and creativity. If you do that, then your brochure printing will definitely improve and your customers will someday say that they read your entire brochure and they got your message loud and clear.