I don't get it: Why Stoics be hating on Epicurus/Epicurean philosophy?

The only real time Epicureanism is mentioned in the bible, as far as I can tell, is in Acts 17, when Paul is in Athens, and some Stoic and Epicurean philosophers ask him about the nature of God. 1 Corinthians 15 condemns people who say that Jesus wasn’t raised from the dead and that people in general weren’t raised from the dead, which would include Epicureans, but also a lot of people.

If you’re looking for condemnations of the philosophy, look to Judaism and the Mishnah, where the term “Apikoros” is used to describe heretics and those who deny God or the afterlife. Apikoros, of course, means Epicurean.

And civic responsibility as such, the way you’re probably conceptualizing it, wasn’t really the same sort of thing in Greece and Rome as it is today.