In general, the onus isn't on you to "expound the numerous facets" - but I think it is on you to expand on your own claims to the point they can be understood; for example - what is a "human right", are you talking about legal rights, or your own opinion; What is a "pregnancy" - do you include all trimesters, allowing abortion up until birth? etc etc etc
Note, I don't really want to get into the discussion, I'm just pointing out no-one could understand you position without follow-up questions.
> There was enough in my statement to squabble over.
True, but the same can be said of any unsubstantial post - you want me to charitably ask for substance, but "unjustified" statements are a dime-a-dozen, and can easily flood a thread - It's just as easy from my perspective to down-vote and move on.
Providing a fuller context in the first place, to me, proves greater good faith wrt wanting a good discussion, and a better guarantee the continuing the conversation will be productive.
Regardless, in a discussion, I don't the onus is on me expound on the numerous facets of the position right from the get-go. Abortion is a topic with many facets. You can't cover it all at once. I mean, yeah, you have to establish a position to start, but not all that much.
I think rather than just saying 'without any justification' you could have more charitably asked a number of clarifying questions or could have taken an opposing stance to argue from. There was enough in my statement to squabble over.