Trust and the Powerful No

I read something this morning by a new submissive that reminded me of how powerful the word NO is to us.

When her Master or Dom agrees to do something even though he doesn't like that thing, her trust falters.  The most demotivating thing you can say to someone who wants to please as their highest goal is "I don't like this, but I'm doing it for you."  

 Can you see her face fall? 
 Can you see her attitude failing?
 You are telling her that her main goal, being pleasing, has failed.
The pleasure she would have taken in that act is draining.

What if you just said no?  She is strong enough to handle it.  She is devoted to your pleasure, not just her own.

"No, we are not doing that today."
"No, you may not do that."
"No, that isn't something I'm into." 
  
If she knows her Dom is able to say no to her, she trusts his "Yes" 100% more, because when he says yes to one of her ideas or suggestions, she believes it will be a pleasure to both of them.

I'm not saying a Dominant can never do things the submissive likes, but what if they phrased it like this instead?  

"I love seeing you in the throes of pleasure. It turns me on as your Master, causing and owning that pleasure."