It only later developed into the general term as opposed to initially specifically referring to Epicureans. See Labendz, "Know What to Answer the Epicurean": A

It only later developed into the general term as opposed to initially specifically referring to Epicureans. See Labendz, "Know What to Answer the Epicurean": A Diachronic Study of the ʾApiqoros in Rabbinic Literature (2003) And I agree - you'd think that given how well known it is that scholarship would engage with considering Epicureanism as a context for a text discussing souls depending on bodies, describing spirit arising from flesh as a greater wonder compared to the other way around, described the cosmos as being like a body that died, and whose followers interpreted its seed parables as referring to indivisible points as of from nothing which made up all things and were scattered in the universe to cause all things to exist.