Scootaloo's inability to fly was well-established in the show. We never got a clear answer for why she can't, but by Season 8, she accepted it as a cold, hard fact. That being said, I still like to hold out hope that someday, she'll be able to fly, and even if she doesn't, it doesn't change who she is: a hardy, brave, strong-willed filly who's endured a lot of setbacks for one so young, and yet has never lost the determination and drive that keeps her going.
This comes from a discussion I had with a friend on a Discord server, discussing one of the IDW comics, specifically Issue 81. There, Rumble takes part in a Foals and Friends Air Parade with the Wonderbolts using a pair of artificial wings, having been inspired by the story of Wind Sock, the only non-pegasus Wonderbolt in history. It's an adorable and believable headcanon that, as Scootaloo is a friend of his, Rumble would be more than willing to let her borrow these wings, so she can feel what it is to fly on her own. It's the same as the headcanon I have that, after Surf and/or Turf, Scootaloo would ask Silverstream to side-along change her into a seapony when the fancy took her. =)