In Season 4 yes Gus is the main antagonist but a majority of the reasons why he stated to hate Walt is Walt's fault. ... Gus had a right to want to kill both Jesse and Walt as killing the dealers could've exposed his empire as did killing Gale.

Why does Walter kill Gus?

Gus was a drug kingpin who controlled the distribution in the Southwestern portion of the United States. ... Gus cared more about Walt's skill and quickly arranged to replace him, something that Walt caught wind of. Walt had no choice but to kill Gus, so he cooked up a plan using his rival's enemy, Hector Salamanca.

Why did Gus kill Victor instead of Walter?

Gus kills Victor because Victor has shown himself to be irresponsible and untrustworthy. Victor has created loose ends, and in many ways his actions exacerbated a bad situation to the point that Walt and Jesse had to kill Gale.