The emotional element does appear to be true, as it's a big part of communication with animals and how they talk with each other (along with pictures). But animals do also seem to be able to understand words, sentences, and more complex conversations.
When you begin interacting with them in this more intelligent way, it opens the door to better communication. It also boosts their self-esteem and confidence just knowing that they have a voice, that you have an interest in hearing what they have to say, and that you think they are smart enough to understand you when you speak to them like you would another human. I've definitely seen results doing this. What about you?