Do you speak up if your point of view differs from that of your superiors?
I'm not a yes person, but I am careful about how I express my opinions. I don't disaGREe vehemently with my superiors or coworkers in front of others. During staff meetings I take notes, formulate my ideas fully, and then present them to the other person privately. You can disaGREe without being disaGREeable. In fact, it's much more likely your opinion will be accepted―and appreciated.
People don't like to be nailed in front of others, and it's a waste of time and energy to cause unnecessary dissent on the job. Private meetings and carefully worded memos that aren't distributed to the entire organization get the message across much more effectively. Few points are worth making at the expense of morale.
How you say something determines whether your opinions will be heard or not. Instead of opening with a statement like, "I don't aGREe with you on the subject of delegation," I might say, "I've been reviewing methods of delegation and have an idea about how we can drive up our efficiency. Would you like to hear it?"