This is an interesting take, but equally makes some pretty massive, and possibly wrong, assumptions.

1. Trusting Italy's numbers.
2. Hospitalisation lasting for weeks.
3. The ratio of sick requiring beds (20%/10%/5%/2.5% etc) and how that moves the day the US runs out of beds.
4. Numbers of HCW requiring masks.
5. Number of HCW in total.

The line I have the biggest problem with is:

"Importantly, I cannot stress this enough: even if I’m wrong – even VERY wrong – about core assumptions like % of severe cases or current case #, it only changes the timeline by days or weeks. This is how exponential growth in an immunologically naïve population work"

I don't have that much time to go through it all, so this will be a very potted analysis buy lets dive in to numbers 2 and 3:

2. All Hospitalisations lasting weeks - this is not true. We do not currently understand the normal disease progression in the most severe cases, but 'weeks' for the majority of patients is most likely not true. Current US protocol is that when discharge is clinically indicated the patient has to have 2x negative test results 24 hours apart, this is quite extreme (but necessary currently) but ads on roughly 1.5-2 days to each stay. Currently, and factoring that all in you're probably looking at 7-12 days at a maximum for an average stay in hospital. Now- as we get a clearer grip on disease progression and what best treatment is, this will most likely decrease. Equally- and this is a bit macabre- quite a few of the most unwell/ frail (those who would take the longest to recover) will die relatively early on in the time, freeing up the beds.

3. The ratio of the sick requiring beds and the affect of that on moving the day the US runs out of beds - The truth is, we have no idea of what this number will be- but currently we are at an (extremely cautious) stage whereby quite a few of the very but not severely or critically unwell are getting beds in hospitals, arguably . As above- with time, disease understanding increases, treatment gets more refined and a need for hospitalisations decrease. However the major issue with her analysis is that there is no acknowledgement of the recovery/death rate in the calculations... this means that this quote: "even if I’m wrong – even VERY wrong – about core assumptions like % of severe cases or current case #, it only changes the timeline by days or weeks." argues against her own point. By changing the timeline by 'weeks' completely changes the nature of the threat she is warning about massively, and by 'days' significantly.

Finally:

"And yes, you really should prepare to buckle down for a bit. All services and supply chains will be impacted. Why risk the stress of being ill-prepared?
Worst case, I’m massively wrong and you now have a huge bag of rice and black beans to burn through over the next few months and enough Robitussin to trip out."

This statement is really not helpful. In an article arguing about how supplies and supply chains will be hit during this crisis, the author is actively encouraging panic buying. Please folks, don't go and panic buy tons of stuff. It's counter productive to buy 300 cans of black beans. Quote from Prof Stephen Taylor: " We know that washing your hands and practicing coughing hygiene is all you need to do at this point. But for many people, hand-washing seems to be too ordinary. This is a dramatic event, therefore a dramatic response is required, so that leads to people throwing money at things in hopes of protecting themselves.”

This is not an argument not take this potential pandemic seriously, but more to encourage people reading both the pessimists' and the optimists' views on this to take a step back and just evaluate the facts being presented, even if they are done so in a quasi-scientific way.