Why do some people take it so personal if others feel different than they do about what happened before recorded time?
Because they are trying to sneak their religion into the public schools by masquerading it as science.
I can't speak for evolutionists, I can only speak for the creationist side.
First, the stakes are extremely high. Emotion that you sense, may reflect the stakes rather than "taking it personally".
But Creationists may take it personally because they feel people are calling God a liar and they love God. It's not unlike saying something bad about your momma.
Evolutionists probably take it personally, because their decision to reject God and live the way they want to hangs in the balance.
Both sides may have invested time and effort into their sides cause and don't want to see that their efforts were in vain.