I think the point being made here is that those systems could also shield Russian infrastructure making it impossible for Ukraine to take those out and making t

I think the point being made here is that those systems could also shield Russian infrastructure making it impossible for Ukraine to take those out and making them unable to defend their country. I don't think the commenter you replied to tried to make a specific point here but they basically said that on the surface there are maybe a handful of areas that are problematic (like national surveillance and missile systems) but when you actually think about it, even defensive systems can be used to shield the aggressors and just like you wouldn't want to see a missile you worked on blowing up an orphanage on CNN, you probably wouldn't want to see the good guys desperately trying to get around your missile defence system and failing. Ukraine is just another war where the good and the bad side is very clear (at least to me as a German). But a lot of conflicts in the recent past might have been more questionable. Also, I think the point the linked article is trying to make is that if we all collectively would refuse to work military related jobs, there would neither be missiles nor missile defence systems. You just couldn't build those. Not necessarily true anymore since we have enough nukes for everybody by now but in the mid 80s this sort of call to inaction might have been more reasonable.