Of course, there are other jobs, but much of it either comes with its own significant ethical hurdles - like fintech, for example, or any form of marketing and much of banking - or is much less accessible (good luck switching fields from eCommerce to embedded programming for power plant equipment or something).
Pretty much only solution I can come up with is seizing the means of production, but that might be an unpopular proposition on this particular website.
I don't see why it's inconsistent. They don't want to be complicit in physical violence and death, but surveillance leads to neither.
2. Dragnet surveillance alone cannot lead to actionable intelligence, it can only be used to confirm other sources of intelligence. The false positive rate is simply too high. Would they still drop that bomb without that surveillance? In most cases, probably.
3. Weapons have only one purpose: to physically harm. Surveillance can have many legitimate purposes. They simply aren't directly comparable.
Those people are software engineers. Unlike you, they could have easily found equivalent jobs elsewhere (almost anywhere) that did not contribute to building a worldwide surveillance network in the name of serving better ads.
I agree with GP that it takes a wacky moral compass to willingly engage in mass surveillance but feel strongly enough about weapons to quit over them. It's either very naive, hypocritical, or both.