Okay, here goes, I'm putting myself out there. As a new fanfic writer, when I see these kinds of critiques on work that is far better than my own it is rather intimidating. If her work can't hold against the criticism then why should I bother?
Every writer is different, tastes differ. Some people attract audiences not merely due to the quality of their work but also for being in the right place at the right time, know the right people who share, and many other factors.
it sort of comes down to why are you writing and whether or not it's still enjoyable to you. Some people become very down because consistent comparisons to other people can be exhausting. It's possible to learn from others' techniques without feeling inferior. And if you're writing for recognition, maybe that's not always the most satisfying approach because fandoms can be fickle, as well as particular, and again, right place, right time, right theme, and that's before even the quality is of concern.
I have mostly been writing stuff that has, by its nature, a fraction of an audience. F/F stories often get less attention in general, then I'm writing about past events, with my PC and an original character, so having realistic expectations is also key. I'm grateful for anyone who takes the time to read and appreciate what I write but I write what I'm writing for personal challenge, skill building, and because I care. Some people do the same but they self-promote and have large networks to share to. Or they have the one or two right people in their networks to share in front of many and the audience grows. Word of mouth is a really powerful thing.
In essence, write for you, enjoy what you're doing. Bounce things off of us, since we're a generally easygoing group who want to help one another. If it stops being fun or satisfying, then don't. It says nothing about you in the end. But avoid comparisons. Learn from what you like and borrow.