Parents complaining about games being too violent - they're the ones to blame for letting their kids play what they deem way too violent. Ya want an E rated game? Go for it! Want a violent game? Get em champ! Games in general shouldn't be "less violent". Game producers can make whatever they want as long as the buyer knows what they're buying.
Should movies be less violent
Should books be less violent
Should plays be less violent
Also, That is what ratings are for, From E-R, A child who gets hold on a violent video game not for their age, That is not the fault of the company. If precious little Timmy grows up to be a serial killer because of the trauma he has gained from playing call of duty, I would personally blame his parents, Himself, Or the people selling the game to him rather than the creators, Since they intended the game to be violent for an older audience, And have no control of a 5 month old baby grabbing hold of it.