This is problematic because it judges human beings based on the value they bring to the state. This is also why "Most of them are valuable workers" is a bad argument. It says we should allow immigration but only if our state profits from it.

If you are against nationalism, you should also disagree with this, as it assigns the interest of the state to be the interest of the population.

Human beings shouldn't be measured by the work they can bring but by the fact that they are humans too.

In fact the workers have more in common with immigrants than with politicians or anyone in power

Yeah, leftist idealism is great when you're dealing with people who share those common-good views, but the harsh reality is that far too much of the world is "dog-eat-dog" (a.k.a. "every man for himself") to be compatible with such ideals. You've got to ensure those you're allowing into the collective mindset are actually part of that mindset, or they will destroy it from within like a cancer.

It's called "nuance," and far too few take the time to consider it, preferring instead to not think and just go with the "all or nothing" extremes. Nuance is something that comes with maturity and a world that forces you to learn it or get screwed. You haven't really changed your beliefs, but rather you've just learned there are practical limitations to everything.

So? Aren't they just wrong? Why reject the whole philosophy because some people are wrong about it?