I don't understand your capacity comment. The original doc estimated 850 per hour on the average (sufficient to accommodate current demand) with room to grow.
850 / hour sounds wildly optimistic for something that can carry only 28 passengers in a pod, but even at face value, that's peanuts compared to what trains can do (especially since travel isn't evenly spread over 24 hours). Trains can easily reach 20-25 times that capacity.
Anyway, it's silly to consider current demand. The demand currently is capped by the time / expense/ inconvenience it takes to get from one place to another. If it really took half an hour, people would start using it to commute, go out for dinner in other city, etc, and one would need to meet demands similar to rapid transit lines. BART can move 25,000 people / hour (and it's full during peak demand). Hyperloop would need similar demand.
Anyway, it's silly to consider current demand. The demand currently is capped by the time / expense/ inconvenience it takes to get from one place to another. If it really took half an hour, people would start using it to commute, go out for dinner in other city, etc, and one would need to meet demands similar to rapid transit lines. BART can move 25,000 people / hour (and it's full during peak demand). Hyperloop would need similar demand.