Uh, yeah the point is that nobody's perfect...
And yes, this might come as news to you, but an awful lot of people really are in great need of reassurance... in fact, quite often the 'shell' or 'wall' that people surround themselves with comes from having been knocked back, criticized, misunderstood and judged so often that they just can't bear to lay themselves on the line to that stuff any more, so they remain cautious and overly reserved in the presence of others.
Also, a lot of the time people are quite confused and they're not sure whether what they want to do would BE an improvement. If they believe they're inadequate in some way and not worthy of other people's respect (due to bullying or other factors), they might not feel that it *is* an improvement to come out of their shell and be more outgoing, or to share their thoughts with others. In fact it's often largely due to this belief that they build the shell in the first place - in the belief that they're protecting a) themselves from more hurt and b) others from the burdens of having to put up with their awful personality (as they see it).
And just to complicate matters more, people are often also in denial of how much reassurance they actually need, or how much others' opinions even affect them. This is usually going on subconsciously, so the person isn't even aware of it in order to make conscious decisions about the rightness or wrongness, honesty or dishonesty of it or to stop it from happening. The self-doubt and low self-esteem is very often covered up and overcompensated for by displays of fake arrogance, aggression, disdain for humanity and "I don't care!" declarations...
It's right that you're responsible for your own actions and judgements, but then this also means that we're all also at least partially responsible for the effects our actions and judgements have on others... which is why I'd say it's important to ensure, before having a strong or negative visible reaction to somebody, that your judgement is indeed justified. Not being able really to ever be sure about that, IMO, since we can't read others' minds, I'd say it's more constructive to reserve judgement.
I guess I just favour compassion over judgement... but that's not just words or some written ideal to me, it's a method or approach that's proven itself over and over in my work as being highly effective at helping people over their social anxieties... the effects of which I've observed in contrast with 'hardline' methods, backed by the mentality you describe, taken by others in similar work, and the low success rates these people get...