No one forces these 70 years olds to work there. I honestly believe that the people who do are happy to be able to earn some money (because they may not find a "better" job).
In Germany no one is really forced to accept a job because of the reasonable good-enough social benefits / welfare systems (not saying that you can live a good life with it though).
Anyway, you probably didn't want to discuss a real issue but rather spread your, umh, questionable ideas about the "army" of immigrants. :-/