Not really that unusual in this day and age with a small business where incoming orders can easily overwhelm and exceed their capacity to get those orders out in a timely manner. They stay open until a certain order capacity is reached; that way they can still get orders out within a day or two. If they were to take more orders than current capacity could handle, then they wouldn't be able to maintain their current turnaround time.
So why not just increase employees and production is what you seem to imply... Well, to increase production would require them to add employees, and with the launch of their fairly recent brick & mortar, they obviously have already done so, but are rightfully keeping from growing their online sales too fast. I've seen many a small business that grows too fast to the detriment of quality control and service and I know Wlad is not willing to go there.
So the simple answer is that if you don't care for the way they're running their online business, then just don't order from them. However, if you're one of their many extremely satisfied customers, you will truly appreciate the quality juices, as well as the level of personal service and quality you receive from them. Their juices are some of the best around, as evidenced by their being at or near the top of so many people's favorite vendors list, and I for one am happy that I'm a customer.