If *all* people had an *innate* aversion to snakes, that would certainly convince humanity that snakes were, if not necessarily "evil," at least always and innately bad.

But all people don't have such an aversion, and it's stronger in some than in others. If necessary, the aversion can be overcome.

Presumably, everyone who has a serious aversion to snakes was frightened by them as a small child - if not by an actual snake, then by scary parental warnings about poisonous snakes.

I think snakes are fine.

Just don't get bitten by a poisonous one. You could die.