"What you permit, you promote."
I couldn't agree less. Where you permit censorship, you promote tyranny. But when you permit diversity of opinion, you promote freedom of thought. That does not mean you promote the content of those opinions.
"I disapprove of what you say, but I will defend to the death your right to say it"
-- Evelyn Beatrice Hall, summarizing Voltaire
It's perfectly fine to be a tyrant or dictator in one's own house. I certainly am. If your house is your castle, then you are king or queen. And if someone doesn't like your rules, then they can get the f*** out and there's nothing wrong with that. You're maintaining a household, not a society, and surely they'll have more fun elsewhere.
But within that household you may be training people to live in a society.
As a general rule, "What you permit you promote" doesn't pass the smell test, not in public; and not even in private. For instance, we all put up with some little thing that we find distasteful when saying "hit the road" would deprive us of other things unrelated to the thing we find distasteful and discourage. For instance, being too dictatorial towards your children may mean you'll never see them again once they're adults. You have do decide whether that's what you want.
Tolerance is not promotion. Tolerance is not acceptance. Tolerance is Tolerance. We don't have a First Amendment to defend agreeable speech. It doesn't need defending. Likewise, there's no need for tolerance for the things we enjoy, accept and promote. It's strictly reserved for those things we don't. It's how a country of millions can get along, and sadly people have forgotten all about that, thinking instead that "tolerance" means "say what I want to hear or STFU", giving us the discord we see every day in the evening news.
On the flip side is consideration. If someone says, "This is my space; I don't want [this] here," then you first check to make sure it IS their space, and then don't bring [this] here. That's just the basic politeness that comes along with "their house, their rules." That's 100% entirely OK, as we all have our space. If you want that for yourself, you have to allow it for others. You deserve what you give.
But in public, in the commons, outside the home and "private" spaces, I go entirely with free expression and the above phrase with which E. B. Hall concisely summed up Voltaire. In the end, tyranny works in a household only because people have somewhere else to go.
Censorship is no way to spread virtue. Virtue comes from someone's own accord, and never from the restrictions that are placed upon him. Tie someone to a pole and he won't do much of anything you don't want him to. Leave him there long enough and you won't have created an obedient person... you'll have created one who will wring your neck the moment he's free.
Withholding permission to dissent from a general populace on the grounds that you don't want to "promote" their opinions only builds pressure and resentment. It creates enemies. It tells them, "You're not entitled to an opinion," and they know this to be a lie. Nothing good ever comes from it.