Same reason jet planes have wings in spite of having a jet engine.

Hmm, something just occurred to me: if S4 states that all pony races must rely on magic, wouldn’t that technically make Winter Wrap-Up unaccomplishable? I mean, the #1 rule of Winter Wrap-Up is “No magic” after all.

@DragonBoi471  
How else would you explain the ability of pegasi to walk on clouds, if not magic? That was introduced during Lauren’s tenure.
 
Even ignoring the cloud-walking, Lauren never stated that she didn’t intend her idea of magic being inherent in all ponies to become canon. With statements like this, it’s pretty clear that that’s simply how she envisioned it working - period - and that, as showrunner and the prime authority for the rules of the MLP world, she made no separation between her “headcanon” and show canon. The only reason it didn’t come up in-show during her tenure was that they never made a story that called for it.
 
Note, however, that in the comment I linked above, she makes it clear that she didn’t envision the different types of ponies being able to express their magic in the same way. It is, as you say, “physically impossible” for a pegasus to perform the kind of magic that a unicorn does.

@Background Pony #BBAF  
But she never intended for that idea `bout “inherent magic” to be canon, did she?  
I’m sorry, it’s just that this idea still bugs me.

@DanielTepesKraus  
No, it’s successor flew. This one broke in half before it ever got off the ground.
 
The person who designed these things wasn’t a fool, either. He just lived before aerodynamics and a lot of modern structural design were well understood. He designed and built the best wind tunnel of his generation. And he is actually the person who proved that thick, curved airfoils produce lift, and produce more lift than thin curves (like a piece of kite fabric), though it was mathematically proposed that thicker airfoils were better before he actually tested it.

@DragonBoi471  
Please explain how pegasi fly with impossibly-small wingspans, then. And how they walk on clouds. And why you’re right and Lauren Faust is wrong about all ponies having inherent magic.

Ahahahahahahahahaha
 
Nice trolololo there… wait were you being serious because then I might have to laugh even harder.

@DoomPony  
What I meant by “Physically Impossible” was that it’s physically impossible for pegasi to use magic. Why? Because pegasi don’t have horns.

@Jim Prower  
That thing actually did fly, btw.

@Ferrotter  
Try telling that to a Formula 1 engineer.

Because everything with wings can fly.
 

To channel it. Moron.

@DoomPony  
Bingo. Everyone go to another image now.

Obviously, it’s because you’d look like dorks with two horns sticking out of your back.

“Magic is physically impossible.” That’s the whole point of magic; making the impossible possible. Flying with tiny wings and making plants just randomly sprout out of dirt are impossible.

@Background Human  
(thinking of Dash doing doggy paddle in the air)  
Pffftttt….

The fact that they can fly with those small wings are impossible. The magic of flight makes sense.

@Prof.NightJack  
Exactly. Though it’d be hilarious to see them “swim” through the sky with their hooves.

Jetpacks are harder to animate.

Watching the episode now. Tirek was stealing the pegasi’s flight & the Earth Ponies’ strength. None of it was about magic at all. This picture & the argument is invalid!

I figure it like this,
 
Pegusi wings would be to small to actually create lift without beating at incredible speed so magic is needed.
 
However just like unicorns need a horn pegusi would also need conductor for their magic and what better conductor/orchestrator for flight could you ask for then wings?
 
In short the magic acts like wing amplifiers,  
No magic = no amplification = no flight  
No wings = nothing to amplify = no flight  
You gotta have both.

@Psychopomf  
 
The key element we’re missing is… thrust!

‘Cause you don’t have jet engines, duh.

Magic provides Directional assistance and stabilization (Pony Tail does not look like a tailplane to me,) and crash resistance/additional thrust beyond what ornithopters should be capable of. Wings provide primary thrust, primary lift, and roll control

I remember this OC’s judgmental face… Hating on muscle fetish haters!