RE: Hard-to-Hard will NEVER result in something GOOD
I'd prefer if you didn't judge the entire society of my country by the clown in the White House.
Trump is trying to appeal to his base with this ham-fisted policy. Compared to Europe, the US spent very little on trade adjustment assistance to help people who lost their jobs due to free trade agreements. This happened around the same time they cut the social safety net. A lot of people are justifiably angry.
Granted, this will only make the situation worse and it won't help them. Honestly, it might be good if Europe retaliates. I don't think that American hegemony is good for anyone, including Americans. But frankly, I don't care if a defense contractor like Boeing gets the steel they need. The defense industry in the US is probably one of the most morally repulsive industries out there anyway.
Boeing is just an example. High grade steel is also used in other industry segments by eg Duracell for batteries, Caterpillar for machines, car makers and packaging and bottling sectors.
Now the EU responded with counter import taxes, and the wish to continue the discussions, I simply hope old of this will not escalate and we can forget about all of this soon.