I believe that it is a matter of balance and what kind of “care” someone has about other’s opinions. The title of this thread could more accurately be: “Spiritually strong people don’t care overly much about everything others think of them.” Obviously, a sane person would care about what others think of them if they were to, say, run outside completely bare-naked, or have sex with a little child on their front lawn while wearing a Donald Duck mask on a Saturday afternoon in front of everybody, or play an Alvin and the Chipmunks Christmas album at deafening volume through speakers facing outward on their window sill at three o’clock in the morning on a Sunday night in the middle of the month of June. No, sir. I think we would all care at least that much about other’s opinions.
But, at the same time, a spiritually strong person – or, more scientifically, a psychologically/emotionally healthy person – doesn’t care inordinately or unreasonably about what others think of them. Such a person has the confidence and security with their ego to go about their lives within a fairly broad range of what is socially/legally acceptable without internalizing and worrying about other people’s parochial and narrow-minded tenants of etiquette, as they see it. I myself don’t judge anybody based on their income, clothing, vehicle or house (or lack thereof), or their ethnicity, religion, political affiliation, or sexual orientation (unless that involves harmful sadism or rape), but the thing that I do judge people on is how they treat others. (I never cared for bullies.) Other than that, I just accept everyone for who/what they are – and I wish and hope that others will likewise be that way with me.
So, while “spiritually strong people” do have some basic “care” regarding fundamental logical social norms, they also, nevertheless, are able to walk with their head up and be proud of who/what they are. The basic “spiritual” principles, I believe, are: Live and let live, love and not harm, respect yourself and others.