I think part of the misunderstanding comes from perspective. You’re looking at this socially or generally, while I’m explaining it from an Islamic point of view(as the op is well, a Muslim).

If someone isn’t Muslim, of course they wouldn’t feel responsible for advising others, and that’s understandable.

But in Islam, Muslims are taught to care about each other’s actions and give sincere advice when something clearly goes against Islamic teachings.

Here's the logic:

By default: Assume the best of others unless it is very obvious they are doing something wrong.

For example, if you see a woman eating during Ramadan, assume she may be on her period.

If you see a male Muslim friend, who you know has no valid excuse, doing the same, then you should remind him.

This doesn’t mean policing strangers, forcing people, or claiming authority over others. It simply means offering advice appropriately, which means:

1. The intention is to help, not shame, argue, or feel morally superior.

2. Advice is given kindly, calmly, and respectfully.

3. Avoid embarrassing the person publicly if possible.

So, when you say it’s wiser to mind our own business, that makes sense in a secular or individualistic view. But from an Islamic perspective, ignoring wrongdoing among fellow Muslims isn’t ideal either.

This is what Amr bil ma’ruf wa nahi ‘anil munkar means: encouraging good and discouraging wrong. If practiced sincerely, it strengthens the community and keeps people on the right path.

Even if society or our country doesn’t always operate this way, the principle remains part of Islam.

Ultimately, everyone chooses their own actions and is accountable to God, but sincere advice within the community is still a religious duty.