Maybe they shouldn't, but when you're going up against the kind of ruthlessness that will stop at nothing to invade your privacy by any means, limiting your angles of attack for ethical concerns might not be palatable for everyone. I'd like these machines to be banned for privacy concerns as well, but if they're banned for safety concerns that I made up, that's still better than them being put in every airport.
That's a dangerous path to go down; if we abandon factual standards or arguing issues on the legal merits, then what's left is basically just marketing. And there will always be someone who can afford better marketing.
It's like torture; one can't torture on behalf of the 'good guys' and say it's for a higher purpose, because acceptance of torture as a legitimate means of inquiry is exactly the sort of thing that divides good government from bad (this, of course, assumes one is opposed to the practice in the first place).
I think the point is that we're already at that place. These machines are only there because of what you call marketing. You may think a knife is an elegant weapon for a more civilized age, but you're still screwed if you bring one to a gunfight. It's a difficult choice.
