Hypothetical? We've seen travel numbers increase significantly over the last decade, and Airbnb now claims a large chunk of that. I think it's important point to remind people why Airbnb exists -- it's a great service with positive benefits. I have stayed in far more Airbnb's than hotels over the last few years, saving money and typically getting a better overall experience.
> Clearly a greater good than, say, having a place to live, no?
This goes back to the first point. Let people build more units. If that doesn't fix the problem, then start evaluating more extreme measures that limit the amount of people that are able to travel to an area at a given time (in the name of making sure people have a place to live.)
To be absolutely clear: you have identified a greater good if and only if your proposed solution for making housing more affordable is implemented successfully.
The post would read almost exactly the same if it addressed your points in the opposite order. Saying it would 'answer' the question as if you're the total arbiter of this is just not true. They're not confused about what you mean, they're disagreeing.
And it's really not a step one, step two situation anyway. Both parts are important at the same time, in different ways.
Clearly a greater good than, say, having a place to live, no?
You have a point with your first paragraph - it would have been a good place to stop. Until the bigger issue is addressed, optimizing for a hypothetical situation is premature.