I’m sure your prof told you that because people will go into ‘Design’ view and just drag stuff around. As an editor, DW is actually quite good, but it’s too expensive for what you get.
If you’re on a Mac, you have options like Coda, Textmate and Sublime Text 2. If you’re on Windows, my vote would go to Sublime Text 2.
All of those things are cheaper*, more light-weight and efficient.
*I didn’t look up all of the prices, but that’s a solid assumption