Let's first remember that though 'God is love.' is a true statement, Love is not His only attribute. Let's check out the rest of them: All-knowing, Eternal, All-powerful, Righteous, Holy, Just.
God cannot be 'more' of one of His attributes than the others, because He is infinite in all of them.
Hell is a place devoid of God. Totally. People go there because they spent their entire lives rejecting God. As such, He will not force Himself upon you after you die, because what will have changed? You will never love Him after you die if you didn't before you did. God is not interested in keeping people out of Hell, He's interested in getting them to Heaven. Heaven is a place of pure love, joy, peace and happiness because God is the source of all of that. Christians are simply in-training to be able to go to Heaven prepared, free of hate, sadness, strife and anger. We are not doing it ourselves. As we further our walk with Christ, He fills us with more of Himself, and as such, we become more of who we were meant to be.
Now suppose God let just anyone into Heaven, sin and all. Those who had trusted in God on Earth are prepared for the inability to sin anymore, and they don't want to. But the sinner, who is still tainted with it, desires to do it, but can't. As such, they couldn't enjoy God and His attributes because they were never open to it. Hell is a self-induced punishment. Yes, it's the place you go for rejecting God, but He gave you a lifetime to see the error of your ways. He sent His children to warn you, He has His Word in every bookstore, His signature is in the night sky, and in nature. The Bible says that foolish men worship the created instead of the Creator. Some worship themselves, some worship women, some worship 'Mother Earth'. Why not worship the One who created everything?
You may ask 'Why can't God just wipe away everyone's sin and let them into Heaven?' Well, do you think you are a sinner? Do you WANT forgiveness? Then God has already offered a way! His Son, Jesus Christ shed His sinless blood on the cross so that our faith could make us blameless in God's eyes. Many people, however, are unwilling or unable to forsake their pride and put faith in the One who gives them every breath they take. As such, because God is Just, and because all of our souls are eternal, He keeps them seperate from those who put their faith in the One who created them and rewards them and punishes the wicked. Let's face it, if the created refuses to give thanks and praise and love to its Creator, it is wicked.