Ramdan: why do people think like this?

okay, i know it's not good to get all judgmental and all, but why is it that when people hear or see others doing haram things, they leave them be and just say "it's not my place to judge"? you're supposed to help others, advise them on what's god and right. not leave them in ignorance and sin. okay, i understand not wanting to look like a hypocrite, cause we all sin. i know. but you can't say "i sin so i'll let so-and-so sin too and just let that be with him and Allah." because you are supposed to warn. how many times in the Qur'an does it mention enjoining piety on others and forbidding them from wrongdoing? so why don't people follow that? and when people do things that they're supposed to be punished for by the community, you hear others just say "it's not my place to punish them, that's haram. it's only for Allah to punish." why don't they realize that Allah is truly the one Punishing them. He is the One Who Sent down the verses telling us to punish them, so why do we ignore that? for instance. fornicators (male or female)are supposed to get the 100 lashes and be banished from the land for 1 year. adulterers (male or female) are supposed to be stoned to death. no question about it. i mean that stuff is mentioned in the Qur'an, so who can deny it? yet when we live in a country ruled by Muslims and the people are sentenced to the fitting punishment, people go and say "that's barbaric, that's not right, who are you to judge?" what is that all about? come on people! yes, we all sin, and we can't say "i'm so pious, i never sin, and i can judge whoever i want, everyone else is a filthy sinner, i should punish them all." i know that would be wrong too. but still, what Allah and His Prophet(pbuh) commanded are supposed to be followed. we can't say no because we don't think it's "nice". wtf is that all about? why are people like that?