Wouldn't it make sense?

Since there are so many claiming that Americas economy would collapse without all the criminal trespers we currently have, Wouldn't it be more logical for ALL the immigrants to leave and allow Americas economy to collapse? Why do they continue to enable Americas greatness? As long as they are here, according to their logic, The American economy will remain strong. If they left, According to them, America would be no more in a very short time. This is a conflict of interest to my way of thinking. What do YOU think about this theory?