It is a very misleading suggestion. sunshinecity gave a good example of helping on his/her kid's essay.
The parents should know how good their kids are at writing and if they need help or not. Very often kids strong in math are weak in language, especially true to the boys. Those kids often write boring sentences, bad logic and sometimes even passive ideas. I have seen my two kids doing it. From experience we got from the first kid's application, we emphasized a lot more on the essay writing on the second kid, which resulted in a much easier admission to top colleges.
"I don't know if you believe or not, I do" :-)
