Okay, this theory is gonna do one of three things. It's either gonna blow your mind, cause you to think that I'm incredibly weird, or both. Whatever the case may be, just hear me out for a moment.

The Basic Premise: Rainbow Dash's actions influence Spitfire more than we think they do.

Basically what it says on the tin. I can't really summarize this without citing my proofs, so let's just dive right in, shall we?

Exhibit A: Hurricane Fluttershy

Let's get the ball rolling with this little episode from Season 2. Spitfire comes down to Ponyville in order to monitor their rainwater collection. Since eight ponies are out with the feather flu, the team breaks apart, and many ponies get injured (though not too badly). Rainbow wants to try again, but Twilight says it's too dangerous. Rainbow ignores her and tries again anyway. Remember this for the next exhibit.

Exhibit B: Wonderbolts Academy

In Season 3, Rainbow Dash is accepted into the Wonderbolt Academy, where Spitfire is her instructor. At the Academy, Spitfire seems to reward the actions of the reckless Lightning Dust. Now, think back to Hurricane Fluttershy. Rainbow Dash wanted to try the tornado again, even though the first attempt was a disaster that might've left somepony in critical condition. Wouldn't you call that reckless? And let's not forget the fact that they still got the job done in the end. It could be that Spitfire admires ponies who push themselves even when things look tough, which is why she rewards Lightning Dust's recklessness.

Speaking of Lightning Dust, we all know what happened to her. She was booted out of the Academy for creating a tornado that nearly took out Rainbow Dash's friends. Spitfire was informed about this by Rainbow Dash herself, who almost quit because she thought that Spitfire was rewarding the wrong behavior. Now, remember this for the last exhibit.

Exhibit C: Rainbow Falls

Fast-forward to Season 4, where Rainbow Dash, Fluttershy, and Bulk Biceps are trying out for the Equestria Games alongside Spitfire, Soarin', and Fleetfoot. Soarin' injures his wing, and Spitfire decides to recruit Rainbow Dash to the Cloudsdale team. And despite what the episode says, I don't think it's because she wanted a better flyer.

Remember, Soarin' told Rainbow Dash that Spitfire told him that he wouldn't be one hundred percent for the tryouts. That tells me that Spitfire didn't want her comrade to fly on an injured wing. Now, imagine if the episode Wonderbolts Academy didn't happen. Would Spitfire still try to recruit Rainbow Dash after Soarin's accident, or would she encourage Soarin' to push himself and fly anyway? It seems by taking Rainbow Dash's lesson about being reckless to heart, Spitfire had doomed herself for another embarrassing miscommunication.

I'll admit that it's very possible that this is all just a coincidence. After all, I don't think a veteran flyer like Spitfire needs Rainbow Dash to tell her that you shouldn't let an injured pony fly, and I highly doubt that she was so impressed by Rainbow's recklessness in Hurricane Fluttershy that she thought recklessness equals results. But if you are persuaded by this, I hope I helped you see Spitfire in a different light. If you aren't, well, there's probably a good reason for it. Heck, even I'm not fully persuaded by this, and I came up with the freaking theory. I just thought I'd share it with you all because I found it interesting. I find a lot of weird things interesting.