Actually, Pinkie went crazy because she thought she’d lost all her friends.
 
Twilight had a breakdown because she thought she’d disappoint the most important person in her life.
 
Starlight lost her friend… And then made plans to take over the world and punish everypony for it.

Am I the only sane one in this land of Technicolor horses!?  
~Spike (PONY.MOV)

@hachebe  
Those were not gags. They were major plot points within the episode. Also, I don’t remember being expected to sympathize with starlight’s backstory. As far as I remember, it was merely an explanation for her behavior.

@Ihhh  

 
YOU keep missing my point
 
Twilight and Pinkie: comedy gag  
Starlight: “I am so sad, my life is a tragedy boo hoo hoo, please feel sorry for me”

@Meh brony  
So quickly that it would break causality and shatter the time–space continuum.

@Ihhh  
Now that I think about the ponies truly are fragile beings aren’t they? Lose a close foalhood friend? Become an insane cultist! Friend skipped out on your birthday? Become a total shut-in who rejects everypony’s efforts to help you move on! It makes me wonder… just how quickly would a pony have a mental breakdown in a world as unforgiving, uncaring and harsh as ours?

@Meh brony  
that’s my whole point.

To be fair all the ponies in the series seem to be a bit… unstable in some way shape or form.

@moonlightaveger  
hi pot, my name’s kettle.

@Ihhh  
Did you take some sort of course on missing the point no matter how many times people explain things? Or is it intentional and you’re trolling us?

@Background Pony #F516  
You don’t know how long it took for her to decline. And it lasted longer because she didn’t have people to help her like twilight and pinkie did.
 
@moonlightaveger  
How is a character losing her sanity over her friends not wanting to go to her party ONE TIME any more relatable than character becoming a cult leader over the loss of her childhood friend? And moon dancer was an adult at the time, starlight was a child, and starlight has shown that she is less mentally stable than moon dancer.

@Ihhh  
The difference is that two of these characters are adults who had a life, what makes their suffering because of the situation believable. Pinkie had a past that we witnessed with those friends and we can understand her suffering. The same with Twilight. The difference isn’t that it is “in character”. The difference is that it’s relatable in a sensical way. Starlight Glimmer is basically a brat that never grew up and had a ~10 years long tantrum because on kid moved out. And this is why I often say that Moondancer is a better Starlight Glimmer. While she did react poorly to being left by Twilight, all she did was shut others out, instead of starting a cult trying to destroy what made others special.

@Ihhh  
Yes, all three reasons are retarded. It doesn’t matter though; her bout of insanity lasted far longer and had much greater impact than either Pinkie’s or Twilight’s did. Additionally, she didn’t have a steady decline in sanity before going nuts, Starlight simply goes off the deep end.

The ponies are just a little emotionally fragile. It only makes them cuter.

@hachebe  
you keep missing the point. People’s problems with starlight seems to be that they can’t buy her backstory and motivation, yet they can buy when other characters do similar things.

@Ihhh  

 
One thing is a fun gimmick for one episode for the sake of comedy, the other is an entire arc for a character we are supossed to feel empaty for.

@hachebe  
That’s not what I’m saying. What i’m saying is that characters do crazy things for stupid reasons all the time, so why is it wrong for one character to do the same?

Make Pinkie or Twilight a little crazy for one episode == An entire character’s arc.
 
Yeah. That make sense

@moonlightaveger  
So what you’re saying is it’s ok for the mane six to overreact because it’s in character, but it’s not ok for starlight glimmer to overreact in the way she did because it’s normal? what?

Actually, Pinkie is insane, period. I’m kidding.
 
Pinkie is an adult whose whole identity depends on making her friends happy. It makes sense that she’d get that bad if she thought she’d lost her friends. Twilight went insane because she thought that Celestia would ruin her life by putting her back in magical kindergarten because she was tardy. That would’ve put her away from her newfound and important friends.
 
Starlight Glimmer went through a normal life event and reacted like her world ended because of it. Kids overreact all the time and grow out of it. SG didn’t.

@Background Pony #374C  
no, but it would be nice.

trying to earn another duck badge?

@Exedrus  
I have dark theme.
 
Can confirm, I could read it.

No background for the text? People using the dark theme won’t be able to read it…

Starlight’s more comparable to Moondancer since she never went insane like the other two, just turned incredibly bitter and cynical.