It’s not because he’s some prude or fancy-pants, holding a fluffy, lace-edged handkerchief to his nose when he pretends to smell something distasteful.
It’s because Sin is to God what Death is to us.
Actually, it would be fair to say that sin is worse than death, because those of us who are believers have the joyful expectation that we will see our loved ones again. Some of them at least.
Sin is the ultimate separation.
Indeed, the LORD’s hand is not too short to save,
and His ear is not too deaf to hear.
But your iniquities have built barriers
between you and your God,
and your sins have made Him hide [His] face from you
so that He does not listen.
It isn’t just that God doesn’t like sin. It’s also that sin builds barriers between us, and while God has made a way to remove the barrier (through his son’s voluntary death in our place) He knows not everyone will jump at that chance.