If you're telling me that pegging the emotional barometer to "happy" all the time is healthy -- then I disagree.
Nah, I didn't say that.
I don't trust plastic people that pin large smiles on their faces all the time.
I think I know what you're talking about, and I mostly agree about "fakeness," but let me present an alternative point of view. I enjoy being friendly to others. It makes me happy. So, when I am down... I still smile at others, and try to treat them well. It helps me to be happier, and I hope it helps them to be happier too.
I don't think that makes me fake or "plastic." I hope not.
That's why I used the conditional statement "If" at the start of my sentence. You didn't mean it that way, that's fine.
While you are correct that mimicing motions of joy can be used to reverse a bad mood, I'm more of the mind that we need both sides of the emotional spectrum to function properly.
There are benefits to every emotion, positive or not.