No more than having. Say. Advanced painting knowledge. Or Advanced cooking knowledge.
Rubbish.
If you are suggesting concepts and don't have a good idea how they will be implemented or what's even possible then you are at an extreme disadvantage.
At the simplest level programmers WILL tell you something you ask for is impossible. Being able to explain how something is possible, and better still being able to show them will work wonders.
But more fundamental than that, if you don't understand how games work under the hood then you aren't going to be good at designing them.
You may be able to drive a car without being competent mechanic but you sure as hell won't be designing one.