Being made aware of the consequences of sin, should not be perceived as an idle threat, but as a fair and compassionate warning.
If God exists, do you think that it is a small matter to deny His efforts in creation, to disregard the ability to love and be loved that He gave all humans?
Do you believe that forgiveness is unconditional - let me see you do the same with a thief - he'll take you for everything that you have, if you don't punish him.
Showing contempt for your Maker is an egregious offense - try showing your parents the same defiance, and see if it doesn't prove to be consequential.
Only the wicked need to be warned of their behaviour, and there is a lot of them. So that any Biblical stipulations that define the ramifications of transgressing God's will, are, first of all, meant for the defiant and insolent, and two, should be considered as full disclosure and transparency.
In other words, you all should say thank you.