Let me guess: That one deep notch in what may be 2013 was when the fandom died. Either Twilicorn, or when the Equestria Girls announcement turned out not to be DHX trolling us but genuine.
 
Remember the fandom died twice in 2013.

Sad but true.  
The show’s writing was all over the place for a long time.

@Background Pony #291E  
Pfft! I bet if we showed our bat ponies to the target demographic, they would like them.

@Fair Use (Optimisitc Neighsayer)  
Until the Gen 5 reboot

@hollowblade  
You have no idea what you’re talking about bro  
Faust and Renzetti’s names are at the very top of every single script until Canterlot Wedding, Lauren wrote the premise for Canterlot Wedding (which includes shining armor, and cadance named as “Ultra Violet”), and Larson said that from his perspective she was just as involved in season 2 as she was with season 1.  
Why do people speak so confidently about things which they know nothing about?  
Lauren once said in a panel that her worst fear from leaving would be that “nobody would miss her, or could tell the difference” and people like you make that a reality.  
https://www.reddit.com/r/IAmA/comments/cezmyc/yo_reddit_im_ma_larson_writer_on_my_little_pony/

Lauren was lucky to have Meghan be able to take over after Hasbro basically shoved her out after season 1.
 
 
@Background Pony #291E
 
Lauren Faust had no involvement with Season 2. She was credited as a creative consultant for that season, which just meant Meghan went to her for advice and the writers were free to do nothing with it. If Lauren actually had her way, Cadence and Shining Armor would not have existed at all.

I just noticed that this graph comes really close to my enjoyment of the cartoon… Huh…  
Maybe I should look for more works by her.

Pony Life is pretty much what critics thought FiM was going to be before they actually saw it. YMMV

Memes happen

Can’t blame Lauren for quitting. Hasbro executives kept changing her scripts without telling her and cancelling episodes at the last minute.
 
For example: There was going to be a bat pony episode in season 2 (Bats are too scary for Little girls!) and Candace was supposed to be a unicorn (We gotta have that pink alicorn princess toy!)

Now let’s hear the theory on what happened in that 2005 spike.

Thank you, Professor Lyra. Very useful.  
I’m just gonna see if this checks.

Trends come and go, pony no different.