@Wiimeiser
There are some “legitimate” reasons, like using the same artist name for your fandom art as for your professional portfolio, and the (assumed) bias people have against fanart when hiring artists. Which if you’re doing porn (particularly fetish porn, which all MLP porn is very much so by default) if fairly understandable.
And of course there’s people that look at stuff they used to draw with dark or fetishy themes and then later in their life repudiate strongly enough to want it gone forever.
The category of “I don’t really participate in the fandom / watch the show anymore, so nuke
everything” is the one I’ll never understand.
In any case, we do always try to offer anonimization / history wipe (including editing out signatures…) when someone asks for a DNP here, but ultimately it’s not our call.