Gun violence in the US is highly concentrated in places you'll never go as a tourist.
Especially in Germany.
I couldn't find any specific numbers with regard to US tourist safety, though Australia's travel advisory does mention the high rates of gun crimes and about a month ago a couple Israeli tourists were shot in Miami Beach.
Again, gun violence would not be my primary concern if I were visiting the US as a tourist, I'm just pointing out that there exists a basis for this concern.
The European preoccupation with American gun violence as it relates to tourism is misplaced in my opinion as tourists are almost never involved. Compare that to the frequent truck/car ramming attacks in Germany which seemingly always kill tourists. Should I avoid visiting German Christmas markets?
Personally I would find such a risk acceptable just as I find the risk of traveling to countries with a high homicide rate acceptable.
But if a friend or family member expressed concern about visiting a German Christmas market due to prior cases of terrorists murdering tourists there I would not dismiss their concerns as irrational or unfounded as there exists a rational basis for this concern.
Yes. Glühwein can be enjoyed in more comfortable setups anyway. If that's your thing.
Is there anything else to marketing X-mas?
What's the reason to drink that stuff there, for usually insane amounts of money, while not much else noteworthy is on offer there, for similar overblown prices, while feeling tense about all the possible shit which could happen, while doing so?