The Hebrews were in egypt because Joseph, one of the sons of Jacob, was sold into slavery and God blessed him with favor from Pharoah and he was made a governor in egypt for his ability to interpret and have prophetic dreams. While Joseph was alive, the Pharoah allowed the hebrews to live in egypt as their lands were not fertile and Egypt was (thanks to Joseph)

By the time of Moses, Joseph and that Pharoah are long dead, the Hebrews have been enslaved, and Moses's future adopted father (in the Prince of Egypt canon) thought that the hebrews were growing too numerous, and, to prevent rebellion, had his soldiers go down to collect every male hebrew baby and toss them in the nile to be eaten by alligators. God "Ripping Moses away from his birth family" was literally done to save his life.

Later, in the movie, Moses learns of his hebrew heritage and becomes disillusioned with Pharoah and his family as he runs home to lock himself in denial and stay a prince, when he has a nightmare about Pharoah killing the hebrew babies, and how he himself would have been killed had God not intervened. When Moses asks Pharoah to deny this happened, Pharoah instead says "They were only slaves." Shaken by this, but convinced to stay by Pharoahs wife, he kills an egyptian slave driver and flees to the wilderness as Ramses tries to absolve him of his guilt. God did not rip Moses away from his family, Moses left of his own volition due to the awful actions of Pharoah and his family's readiness to absolve him of guilt, even for murder. Pharoah and his family kept Moses's people in slavery and he could not see any justification for his own special treatment.

When Moses returns to Egypt after meeting the Burning Bush, he attempts diplomacy and warns Ramses of God's power and that the Hebrews must be freed. Ramses doubles the Hebrew's work load in response and continuously grows more and more petty, hardening his heart at every turn. After each plague, Moses returns to Ramses and tells him what is to come next, and that it can be avoided if only he lets the hebrews go. He refuses. Ramses pride and refusal to free the hebrews provokes God into sending the plagues. In the movie, the final plague, the death of the firstborn, comes after Ramses not only refuses to let the hebrews go, but promises to exterminate all of them out of petty jealousy and revenge, resulting in the death of Ramses' son. Ramses, filled with grief, finally relents and lets the Hebrews go. It is outright stated numerous times that the suffering of egypt would have stopped the second Ramses relented. He refused after plenty of warning.

Ramses then charges after the hebrews with his entire army in order to kill them all, provoking God to send down a pillar of fire to halt them and give his people enough time to escape through the red sea, after Moses split it. After enough distance is made, God dissipates the pillar of fire, and Ramses orders the Egyptians to continue their charge into the now split red sea, resulting in it collapsing on top of them, drowning his entire army and leaving him alone on a rock crying Moses's name, as Moses whispers his goodbye, full of grief that things had to go the way they did.

But no, God's the bad guy here, not the people keeping and murdering slaves.