I also don't get why ppl say BB is the easiest of them all.
Sure, ppl who played DeS,DaS,DaS II are going to be more trained in souls games even if the mechanics changed a bit. But i think that people who play BB for the first time have it harder compared to the other games.
Other games have shields where you can hide behind and survive a lot of encounters with doing little offensive action. Can't do this in BB
Other games had magic and bows to cheese 50 % of the enemies from far away. Starting DeS with Royal and the harry potter soul arrow made the game and bosses incredible more easy (Flamelurker is a joke with soul arrow).
Good players played the souls games only two-handed, rolling and doging a lot - no wonder that they breeze through BB, because the mechanics empower exactly this.