Marauders fans keep shitting on teenage snape for joining the death eaters (which shouldn't be condoned at all) but, like:
The marauders set a werewolf loose for their personal pleasure. Lupin states there were quite a few close misses, Sirius doesn't deny it. None of them except for Remus ever show any traces of guilt.
They created a map which showed positions of people on the map, a serious breach of privacy and basic regard.
Even within the group, they treat each other terribly. Sirius appeared to have great great disregard for Peter's abilities, and used Remus' werewolf form 'as a prank', which could've resulted in horrifying consequences for Remus. James and Sirius chose to trust Peter or Remus on ?? grounds. I could go on, actually.
They became animagi illegally, hence effectively establishing themselves as juvenile delinquents.
James was implied to hex other people (depending on what those hexes were, in atleast some cases, the muggle equivalent of it would be physical assault).
I'll be honest here, I have very ambivalent feelings towards Snape (partly because in my eyes Rowling wasn't able to do him complete justice as a character). But, the double standards make my head spin sometimes.