ויתרוצצו הבנים בקרבה

Rashi comments that when Rivka passed a Beis Medrash Yaakov tried to get out and when she passed a house of Avoda Zara Esav tried to get out.

That obvious question is was Esav a Rasha already in the womb? What choice did he have there? Did he even have a Yetzer Hara before he was born? The same goes for Yaakov. Chazal state that a person's yetzer tov doesn't enter them until the age of 13, if so, what drove Yaakov to the Beis Medrash?

The Maharal gives a very perplexing and difficult answer. He says that Esav was not propelled by the Yetzer Hara to go to the house of Avoda Zara rather that was simply his nature. The same with Yaakov and the Beis Medrash. Esav's innate nature was drawn to tumah and Yaakov's was drawn to kedusha.

This Maharal seems to contradict a fundamental principle of Judaism that every person has free will and can choose to be a Tzadik or a Rasha. If Esav's innate nature in the womb was to worship Avoda Zara how can he blamed for his actions, likewise if Yaakov's innate nature was for kedusha why should he be rewarded for that?