it kinda looks like it’s moving.

@CogWeaver  
I like Derpy’s other ships more, personally. :)
 
I mean,  
1 - the Doctor is an exported character at this point and though it’s possible for him to exist very nearly canonically (heck, IDW could publish it and noone’d be surprised) he still doesn’t quite fit into MLP or it becomes a different show.  
(And if you play Doc as a more generic time traveller or a normal pony then you’re destroying some of what makes him popular.)  
2 - there’s no way to imagine the relationship NOT ending in tragedy eventually. She WILL get sidelined for some bs “greater good” reason at some point. And I want my grey pony to be happy.  
Plus, even though the occassional tragic Derpy is fine, constantly being pushed into that role kind of gets tiring, and doesn’t let you see some of the more MLP-ish aspects of the character.  
And if you play the Doctor as a guy who’ll eventually settle down and grow out of being dark and moody - well then you’re cheating the other character’s shtick and that doesn’t work either.

I think this is pretty much the one and only ship the fandom can agree on. Not even the married couples have the kind of tranquility among the fans that this ship generates.

I’ve always loved this ship.