If punishment deters people from such bad acts, this world would be a better place.
And you know how much pain the said acts cause, maybe you don't, but they are people out there who have their cars stolen, computers, jewelries, money. I've seen heapes
of cctv of gunpoint robberies in US itself. Imagine how the victims feel,

Also try to imagine when the one true love of the life of a man or women, whom they trust so dearly, sleeps with another man. Can you imagine that? I've heard of stories where they became so broken that they turn to murder their wife and her lover and even suicide.

About drinking, do I have mention how much problems it causes?

Where is justice for the victims if you're going to let thieves and others off easily?
Islam maintains peace and safety for everyone in the community.