For a while I worked at a company that did arguably worse things than Google does. Regardless of dignity and courage it's hard to just "walk away" from a paycheck when you have mouths to feed, a mortgage to pay, a family who gets sick and needs medical care, pets, hobbies, whatever. There's also the fact that for most of us work is a huge percentage of our time and our social lives can be deeply intertwined with our work lives--it can be a tough decision to walk away from all your colleagues and friends who you enjoy working with even if you don't particularly enjoy the work itself (sometimes shared hardships and commiseration can make those bonds even tougher to break).
Expecting engineers to die on this hill for us seems incredibly unfair. To balk at someone not upturning their life and (under the US healthcare system at least) endangering the health and well-being of themselves and their families in the name of dignity or morality when the net result of doing so would be exactly zero because Google can replace them in a heartbeat is, in my opinion, a gross and unnecessary misdirection of blame.