By "controlled" I had something else in mind than what you seem to insinuate, namely that the yearly immigration rate must roughly match the desired long-term population stability. For a reasonable immigration system, you need to welcome the immigrants you want to get, provide a long-term perspective, and offer some incentives for them to come. Unlike the US, European countries have often failed at that basic job, or at least their immigration politics have been erratic and without constancy. Phrases like "a stance hard enough" are a symptom of the problem.
The biggest failure is that part of "provide a perspective" - not even a long-term. Immigrants were accepted and... that was all, probably expecting the invisible hand, or Santa, to magically sort stuff up. And then acting surprised when immigrants who were denied the right to work looked into, ahem, "alternate" income sources, or original cultural behaviors got carried over. One could even get the idea that all these failures were by design to keep a handy scapegoat for their own failures (or misdeeds). Thus the anger of the alt-truth crowd not only with said immigrants but also with the system which failed everybody (except the system people).
