Like I said before, it's because Wolf's attacks actually move him forward. Falco has like two attacks that do that they "inch" or "centimeter" their way. The thing with Falco is that he's got good, strong attacks, but suffers from being unable to actually hit them reliably like Wolf. Fox in contrast has fast attacks that he can constantly chain over and over, but his issue are kill moves. I don't really know about Fox, but I think he only has Up Smash, Uair, Bair, Fair, Side Smash, and maybe Down Smash as kill moves in SSB4. Falco on the other hand has Utilt, Up Smash, Uair, Fair, Bair, Side Smash, Down Smash, Dtilt, and even B-throw, U-throw, Falco Phantasm - his most reliable meteor - and Dair - his unreliable meteor. That's 12 to Fox's 6! Amazing? No, since if Falco can't land them, it's freaking worthless and sometimes if he lands them, he might hit them too hard early on and they're barely pass the blast line meaning characters like Pit can just (literally) fly back. At least Fox can quickly get in and Up Smash someone.
Wolf is like a balance where although he's slow, he has fast, moving, or well-ranged moves. That means Wolf can reliably chain and kill. Ironic since he's the heavyweight compared to Fox and Falco, but in a way, it makes him much more unique. Fox and Falco are like Ryu and Ken; Wolf is more like Gouken or Akuma or for a more drastic difference: if Fox is Kyo Kusanagi, Falco is Iori Yagami (with flames), and Wolf is Iori (without flames).
Why two Iori's? For KoF players, then they're aware that Kyo and Iori began as clones, but later on became semi-clones. They were less clone-y than Ryu and Ken. Kyo's fighting style was based on Kenpo; Fox's fighting style is "grounded". Iori uses a fictional martial arts that mimics using claws - his claws are his hands; Falco's uses his arms more and he is kind of more "out there" and less "grounded" or less "realistic". Now, in XII, Iori loses his flames meaning he fights entirely with martial arts and man, is he a savage, but awesome fighter who is slow, but if he gets in, he starts (literally) tearing -bleep- up; that's Wolf.
Anyway, Falco is really feels like a mishmash of characters. I think if he was a bit faster either through faster attacks or movement speed, he'd feel much more fluid. As of now, he's like Ganondorf, but without reach and Ganondorf's raw power. At least Falco can recover reliably and combo more than Ganondorf... Oh, and Up Smash is kind of annoying at times. When it hits: awesome; when it doesn't: WTF?! His foot freaking went through the damned... ARGH!!!
Still, he's not bad, but he's not amazing. Thankfully this game can be patched and was fairly balanced out of the box compared to Brawl. We never ever want to see another Brawl Ganondorf again.