The lower ranking members indeed are gangbangers or cholos like they call them in Mexico. The way they dress is nothing cool about. From the middle and upper management level of a cartel there hundreds of different people whom all dress differently. It isn't a corporation who lays down the dresscode or something. There are old guys who walk around in flip flops and then there are some who walk with a cowboy hat. The younger powerfull guys usually dress to impress but other than that there isn't a specific way the stronger members all dress alike.

And people that join the cartels, choose for a life of crime like any other career criminal: for the money and not because it is an ''exciting career with many benefits''.

Btw The Zetas are split up again I think there is a war between the older and younger generation. With the older guys going for the name Escuela Vieja and the younger guys cartel del norte. But it isn't 100% clear yet what is going on aside from the killings and 2 factions insulting each other with banners.