I don't think they're entirely new, but consider that the average tech employee is in their late 20s or early 30s and the only major exercises of US military power they've seen were in Afghanistan and Iraq. The US has squandered its goodwill among that group by engaging in wars of aggression that were only marginally necessary. They didn't experience the cold war when the threat of nuclear annihilation was hovering over everyone (until very recently; it seems to be returning). Couple that with the highly employee favored labor market dynamics in tech and it's not surprising people don't want to take military applications up.

Also, it has to be said: it's a verdict on US leadership. The man in the oval office isn't someone I'd feel comfortable arming, nor was Bush. Even Obama had the thing with the drone strikes. When US Presidents demonstrate carelessness and unpredictability in their use of force, it turns reasonable, peace-loving people off.

That unraveling of goodwill began much earlier, with Vietnam, imo.