Majority isn't always right. Suppose the society says, "Kill yourself", would you do it?

Ignoring the fact that everyone would never agree on anything, even if they did it would not necessarily make it right. They would think it was right, but morality and ethics are subjective between populations. The only possibility for objectivity is through deductive, impartial analysis (as improbable as total consensus)... and even then I doubt the majority would go along with the reasonable approach. Call me a cynic.

It depends on how you define "good", and good for whom exactly? There are things I think of as being "good" that I'm sure most of society does not. And I know there are things society thinks of as being good that I do not.

Take into consideration, the Salem Witch Trials. That society thought girls who danced naked in the woods, and old women who had no home to live in were best to be hanged.

If you actually look at there are only a few topics which everyone in society agrees on

1) Crimes like murder,looting,rape etc. should not be accepted

2) Charity is good(Most people agree on that 0.00001% don't).

Then all other subjects is debatable.On those issues there will be a noticeable group of people who benefit on what society does not agree on hence society is not always right.