Yes, but Toxic Orb is still better. Anyway, there's no doubt Swellow can hit things hard, but you need to consider that there is a lot of Pokemon that can counter Swellow with ease, exploiting his switchineritis (thanks Mekkah). Having said that, there is even more Swellow counters in UU. Aggron and Probopass are pretty much the perfect definition of a Swellow counter, and many others aren't far behind.
He's easily knocked out by a surprise Choice Scarfer, an unexpected Focus Sash lays waste to him, and if the opponent has any form of offence, they will OHKO provided they survive the Facade. He's pretty much a faster version of Pikachu, albeit more restricted. Whereas Pika can deal both special and physical damage with moves like Surf, Grass Knot, Thunderbolt, Focus Punch etc. etc, Swellow is limited to Facade, Brave Bird, U-Turn, Steel Wing and maybe Pursuit. This makes him very predictable, and very, very easy to counter.
I'm speaking with experience as I have battled with Swellow a lot, and he has won many battles for me, but all the opponent has to do in switch in Skarmory and I'm back to square 1. Then I gotta struggle to switch him back in, which usually involves sacrificing a Pokemon and getting rid of Stealth Rock. And if I haven't got rid of Skarmory yet, I've wasted my time, because he'll switch back in.
It's easy to be blinded by his power and speed, but he's the sorta Pokemon that will fall flat on his face against any well made squad. As a late game sweeper, you can do a lot worse, but if we're limiting him to the OU metagame, you can also do a lot better. As a Choice Bander, he's eclipsed by Staraptor, as a Guts user he's eclipsed by Heracross, and if I wanted to use a fast, hard hitting bird, I'd be using Aerodactyl.
EDIT @ Wish Hax
Why is this exactly? I don't see why it's better over Flame Orb, when they both have the same effect in the end anyway. Mind explain, please?
I have sent a PM explaining, so as not to go off-topic in this thread.