Mexican Maids who speak very poor English

On the topic we briefly discussed in class (brought up in the syllabus), I have noticed a growing trend in the Mexican maid who speaks very poor English on a number of television (both fictional and "reality") shows including but not limited to: Rosario on Will and Grace, Lupita on Weeds, Zoila on Flipping Out, and another whose name I am unsure of on The Real Housewives of New York...
They are typically older Mexican women who act as a comedic relief in the show and speak very poor English. They are also often made to do things their employers do no wish to do.
Although I do realize that Mexican women do take jobs as maids or housekeepers, i rarely see Mexican women portrayed in television shows in any other large trends.