@voodoo91  
It seems kinda obvious to me that Alicorns are meant to represent the combined strengths of all the Three Tribes, and that some are born to greatness while others have greatness thrust upon them. the show doesn’t really need to directly quantify it as far as I’m concerned, I’d honestly prefer that there was room for fans to interpret canon events as they please, it’s what allows so much room for fan content.

I suppose at this point were just going to have to accept that the whole alicorn thing will just remain a mystery. It’s not genetics, because that doesn’t explain how Twilight achieved it, and it’s cant be a simple matter of merit , due to the matter of Flurry heart being a baby who really hasn’t done much. Fact of the matter is, the writers are probably never going to explain it because once they do its a canon and that might interfere when the next batch of toys needs to be pushed out. Besides at this point I highly doubt they could give us an answer that would make any sense.

@MrSeyker  
NO U

I do hope nobody ever asked this question for real. Because damn it is dumb.

@JaggedCarpet  
My headcanon is that a Pony has to have the blood of all Three Tribes in sufficient relative genetic percentage for alicornification to even be possible in the first place, but that by this point in Equestrian history more than half of the population is probably eligible thanks to the Wow That Pony Is Hot factor. Flurry happened because she had a mother whose DNA was (altered to be nearly) 100% Alicorn, and a father whose lineage was demonstrably already primed for alicornification.

Luna and Celestia were born as Alicorns, so we know that there are natural-born Alicorns in their world. Cadance is an artificial Alicorn, though, so who knows what happened? Maybe there was some distant Alicorn ancestor that happened to appear with the help of her own Alicorn body?

Oh, if only the show had included some dialogue about how utterly unexpected and unprecedented Flurry Heart’s alicorn status was.
 
@The Walhi Llama  
So, is your position that Lauren Faust intended Celestia’s and Luna’s backstories to show that they earned their alicornification, or is it that the show’s writers haven’t bothered to care since the beginning?
 
 
@Background Pony #F19D  
Glad you put that spoilered bit in there, since some people actually do believe that (though they don’t phrase it as the show supporting Nazism, of course).
 
@Background Pony #F19D  
I think you’re confusing headcanon with canon, there.

@abortedfetusnecrophiliac  
toughest and most determined
 
…Also wow, I had no idea we had a Legendary Imgurian here.

@TexasUberAlles  
The sperm that impregnate are actually usually the last sperm. It takes multiple to break the ‘barrier’ before they can ‘get in,’ so to speak.

She did do something great– she swam faster than the others.

@Zarkkarz
 
Then how do you explain Blueblood?

All ponies born into royalty are alicorns.

@Dirty Bit  
Yet with magic involved alicorn form could have been just a transformation. Did Twilight’s genes change when she turned into an alicorn? Can genetics alone serve as a reasonable explanation?
 
Also, I said that before but if two people with a lot of muscles have a child then the child isn’t born with a lot of muscles but it still has to earn them through training.
 
If children could inherit the abilities their parents earned throughout their lives then humans would be OP.  
Ponies too for that matter. Also alicorns would be running about everywhere. Don’t tell me Celestia never had any children.
 
Also, what do you get when you mix a pegasus and a unicorn. With genetics you could have both a horn and wings or neither or just one but that doesn’t happen with ponies. Also look at the cake twins.

@Magic Nova
 
@PonyPon
 
What I love about MLP genetics is that someone actually went out of their way to make a chart based on the very concept XD

@Magic Nova  
Excuse us for thinking ponies weren’t beholden to that.  

@Background Pony #22D3  

 
 
Yeah, father is a unicorn, mother is a alicorn, 50% chance the foal is going to be a alicorn. Its not hard to understand basic genetic reproduction.

@Dirty Bit  
Yep, pretty much that.

@Background Pony #F19D
 
Well, there is that. I mean, in the case of Flurry Heart, it’s as simple as merchandising.
 
While definitely a good show, MLP is still a franchise based around toys and merch.

@Dirty Bit  
I think Toriyama said he simply forgot about it.
 
Being alicorn is like the super saiyan of mlp. It turns into a joke after a while.

God, I hate this question.

That’s like asking why Trunks and Goten weren’t born with tails

Flurry Heart being a secret Changeling agent confirmed.

You see that’s why mlp actually supports nazism.  
They show some races as Übermenschen with superior genes while others are Untermenschen with inferior genes which is racial ideology.  
I’m just kidding, guys. Don’t take this seriously.

It’s almost like to show never actually said that or something

It’s called the writters can’t be bothered to actually care anymore.