It's just that series 4 was so damn mediocre compared with all the others, even series 1.
They won't top the series 1 finale.
The only good villains in series 4 where the Sontarans, The Daleks and Davros.
All the other series.
Best villains of series 1: Dalek, Dalek emperor, Gas Mask child.
Best Villains of series 2: Cybermen, Werewolf, Cult of Skaro, Sycorax, Krillitanes, clockwork robots.
Best Villains of series 3: The Master, Weeping Angels, Judoon, Cult of Skaro, The Family of Blood.
Series 4 was good, it just wasn't as brilliant as the others, Catherine Tate was awful, and the monsters where just bland and forgettable.
You can't compare a giant wasp to the cybermen.
Or a living shadow to the weeping angels.
Sure, Davros was good, The Daleks where good, but as far as I'm concerned anything with the Daleks will be good.
It's not just villains though.
There where so many good moments in the other series, a short list...
k-9!
Sarah Jane!
Regeneration!
Army of Ghosts cliffhanger
Jack in Utopia.
The Master revealed.
The Vote saxon thing.
Bad wolf.
Torchwood.
Series 4 had... What? Rose? The let-down of the Medusa cascade?