All consulting positions are not created equal. For example, you can be the eternal consultant with a company like Microsoft where you're nothing more than an employee that they don't want to pay benefits to. You can also find consulting gigs where you are able to do more solutions oriented consulting. Typically, the skill and quality of the solution oriented consultant is higher than the staff augmentation consultant. However, not all consultants understand the difference.
As a contractor, your responsibility is to provide service to the customer at the best quality and shortest time that you can. Some consultants just don't get that. They try to act as though they are employees of the company and end up causing lots of problems. Consulting is not for everyone, and before you jump into it, you should look at the environment and make sure you understand it.
I guess this is why many companies have had real sour experiences with consulting. I think I'm funny, but I'm a highly paid consultant and in many situations would recommend that people hire full time employees over hiring consultants. If people have something to loose (getting fired for example) they behave differently and are more engaged in the company. They're also harder to get rid of if they're morons, but such is life!