Do we need to keep making personal judgements to keep the social ones going? Was it really a bunch of people idly judging that really lead to the formal ones to be defined?
IOW sure if objective judgement is needed towards some utility - making formal/societal ones - do it. The point like with every 'don't' is not to say don't judge no matter - point is don't generally judge unless it is fair/useful/targeted towards general betterment.
I think there is inherent value to openly judging people, and there is nothing inherently wrong with having and expressing "negative" emotion. IMO where we are actually failing as a society is in our acceptance of /being judged/. And I do not mean acceptance in the way where you must feel positive about it - my point is exactly the opposite; openly judge them right back. If two people judge each other harshly and also are accepting of each other then they may still carry on with seizing opportunities to help each other rather than creating distance and trying to forget each other exists. Over time, the confrontation is a catalyst for evolving our behavior with each other but only if we are all accepting of being judged
If I am truly honest, I think it is ironic to preach for people to not do something (like judge) as a means of supporting an acceptance of people's behaviors. I feel like there is an underlying assumption to your stance that judgement and harsh language is inherently bad. You can both accept someone the way they are and judge them for it.. and I personally believe it is /required/ to accept them the way they are in order to provide a more "objective" judgement.
edit: to answer your question, yes i believe idle judgements are the grassroots to future formalized societal rules. formalism is a well studied idea in philosophy and is ultimately a self sustaining illusion built upon informal phenomenon. In other words, you cannot create a formal system to govern subjective behavior without informal subjective behavior laying the groundwork first.