Simple really because islam tells people to not drink alcohol for it makes you do things that are not moral and harms your body.
Tells you not to have sex with women without getting married first.(having sex outside of marriage ruins family structure)
So basically most of the people really want to drink and have sex with any girl they meet that's why.
But most important thing is islam wants you to worship only one true God not 3 or wooden idols, also there is the thing about lucifer
He asked God to give him some time so he can prove humans not deserving to be the rulers of heavens so God gave him time to do his best
And said I know things that no other knows you can go and do whatever you think is best to turn them away from me but I know better.
Since Islam is the last religion lucifer(satan) is doing whatever he can to crush it.
Just put your self in his shoes, then you would understand that you will grow more and more to hate humans and you would do anything
To have your revenge on them.