All it is saying that certain ones have a right to life. For viable, it is easy to substitute any number of qualifiers:
Satisfying, productive, painless...
I understand how one might look at such an admission as hopeful. I find it distracting for the real question at hand.
Cordially.
Setting magic thinking aside (the thinking that postulates individual human existence --as a person-- begins at some later stage following conception, perhaps late in gestational existence), we get a clearer picture of the scientific truth: every individual human being alive today had the beginning of their individual human existence at their unique conception; life support for their individual human existence was given via a womb, then a life supporting soul(s) in order to make it through cribhood, toddlerhood, etc., stages of their continuous existence. The individual reality of an individual begins at conception. That is scientific fact, though some try to argue that since twinning may occur early in life, there must not have been an individual present yet --which is of course an absurd notion 'akin' to saying a woman has no individual existence since she may conceive in her womb a unique separate individual.
The most absurd qualifier is also the most demonically subtle : conception doesn't begin an individual human life because ... add any notion desired. There is no 'because' : taking just the twinning argument, if a first individual life hasn't begun then a second individual life couldn't begin at twinning, thus the fall-back to magic thinking that individual human life must begin at some later stage, a stage these qualifier champions never seem to define, I might add.