Skull Arch fiend was an example... heres a better one Brain Golem + Nefas = 3500
Belial Marquis of Darkness + Nefas for 3800 Atk.....
So this monster isnt as bad as you say it is, and it fits into almost all fiend based decks.
You've done nothing to prove your point. All the card is a beatstick and all the monsters you listed are bad. No one runs either of those.
The only good "Fiend" deck is Dark Worlds, and they don't have the space to waste time on this guy. The card is pretty much useless now, because a beatstick is just bad in this format. We have Inzektors, Dino Rabbit, and Wind-Ups, all of which have easy outs to this guy, one of which being the most commonly run Trap Card in the game, Fiendish Chain, Effect Veiler, not to mention Inzektors would nuke the guy with Hornet, Dolkka and Laggia would kill him cold, and Wind-Ups would need a little more, but they could do it just the same. It's not a good card except for very, very casual play.