Why duz society hate gangsters?

Seriously why duz society hate us? Nortenos are just a organized gang that shows pride for the mexican betterment. Like cesar chavez we help our mexican comunity for more respect to the farmers. Yeah sum do kill but surenos a.k.a(scrapz) usualy start things and kill ours so we retaliate. But yeah why do they hate us wen sum of us only are in it for the mexican betterment.??