It is the same as stealing. Try it in college and see what happens. They will throw your sorry rear end out as a cheater.
Take credit for someone elses work. They work hard to write it and a thief copies it as their own. Smiling as if they are actually smart enough to write it, and all the while knowing that they are a liar and a thief. What is even better is when they try to tell others how low the others are and how great and knowing they are. "Look at this article I just wrote". Yeah, impressive, except you forgot to tell us that you copied it word for word and forgot to give the real author credit. Self esteem problems?
I wonder who would trust such a person? Would they steal your money if you let them into your home? I would not put it past them.
Here is a little something for all of the plagiarizers out there: http://www.plagiarismchecker.com/
Real easy. Simply cut and paste the persons "essay" into the checker and voila, you get a report. One person on AR that I have found does it almost every blog. And they want clients to trust them. I don't think so.