I was being very honest, it is hard to start educating someone coming from that position since there is so much bullshit wrapped around a statement like "unions are just corporate blackmailing" which is hard to pull apart without knowing how the person came to that conclusion.
I don't even think it's possible to change someone's mind who already think that way, since it's purely from a point of absolute ignorance and I'm not willing to put enough effort to cite literature that could give them good starting points to understand something they are very likely not even willing to start understanding. They have a lazy position, I reply lazily.
They have an ideological position, based on ignorance, and from a single statement it's pretty clear they aren't curious and willing to change their mind.
Hence why I cite to look into how unions work in the Nordics, at least that is a starting point if they want to learn more about labour movements. It takes someone being curious though.
In the end, it was absolutely honest: it is hard to start educating someone who holds that position a priori and based on pure ignorance, and if not ignorance it's maliciousness, there's not much of a spectrum in this case.