Illegal immigrants do need to be granted legal pathways to citizenship, but there should not be a blanket policy that if you hold a job then you become a citizen. There need to be extensive background checks to make sure that the worker is not a criminal, and is going to be a productive member of society.
To be a legal citizen, the standard should be much more profound than merely "holding a job." For example, how long as the illegal immigrant been here? Have they committed any crimes? How did they get here? Did they jump a fence or merely overstay a visa? There are other factors that need to considered before citizenship is given to someone.