Can someone explain to me why this does this cause it's not my fault it wasn't approved? Thanks!

Refer to topic #23578.

Posts not approved within 30 days are likely because they do not meet the minimum uploading requirements.
Approvers are reluctant to approve it, thus it gets passed around for other approvers to look at and make their judgement. If no judgement could be reached within 30 days, it gets automatically deleted.

In your case (i.e., post #4682548), it is likely due to the character being too humanlike.

If you think the auto deletion is in error, feel free to appeal to NotMeNotYou since he deals with auto modded deletions.

In this case, humanoid characters can be tricky at times. For example, some Pokémon can look annoyingly like a stylized human wearing some sort of costume, especially when pokémorphed. A lack of nose doesn't count as nonhuman enough or Finn from Adventure Time would be nonhuman, nor do funky skin colors or the Simpsons become acceptable.

In your case, had I run across it, I probably would have accepted it as the hair looks like it's made of fire and a human whose hair was on fire would not be all that interested in posing sexually for the viewer. I can't read minds, but I'm guessing that the Janitors who did see it likely couldn't decide if it was indeed fiery or not and so skipped it for later or for someone else to judge it. Then the auto mod ate it before someone could. Hence why we have the option of appealing it to NotMeNotYou.