I find nothing depressing about freedom of speech. It's actions that concern me. And the actions of the Federation were never shown to be right in the show...ever. So, I can't find it depressing when we are literally told they are wrong and being manipulated in some manner.
Just like in Insurrection, inter Arma Enim Silent Leges, Homefront/Paradise Lost, The Undiscovered Country, among others. The Federation not willing to recognize the wrong and not reversing course would be depressing. That wasn't the case here.
Freedom without responsibility leads to destruction. The Federation is a (mostly) enlightened society where people are mature enough to handle their freedom responsibly (as opposed to us 21st century humans, but that's a discussion more suited for TNZ).