On the contrary of your belief,
I think your point plainly shows the author point of view
"distributed systems are a UX problem".
Or in other words a "business problem"
which cannot be solved only at the system level.
In your case you choose to minimise the risk of not fulfilling an order
by having a shop per stock.
This is a perfectly acceptable choice.
But there are other options which maximise sales opportunities
at the price of more risks, which have to be compensated in turn
by a whole chain of business/logistic/human/technical processes and mechanisms.
I wasn't aware that I was disagreeing with the original author. I think the point made by the article here is a valid and useful one. I'm just agreeing with an earlier poster that one possible strategy for dealing with this issue is to change which parts of the system are, effectively, distributed.
If the customer is directly exposed to a distributed ordering system, then it is inevitable that they will sometimes see symptoms of the kinds of technical problems we've been discussing. However you dress it up, that is never going to give the ideal buying experience to all of your customers all of the time.
On the other hand, if you can shift the distribution mechanisms behind the scenes, you still have to deal with similar sorts of problems, but only internally. Your staff can be trained to understand and deal with the kinds of race conditions and scheduling conflicts that might arise, and they aren't going to get upset and take their business elsewhere the way an angry customer might when those things happen.
I better understand now the distinction you make
between a distributed system
and a distributed system directly exposed to the customer.
The former is a fact we have to cope with,
while the latter is definitely something we can and have to minimize.
In your case you choose to minimise the risk of not fulfilling an order by having a shop per stock. This is a perfectly acceptable choice. But there are other options which maximise sales opportunities at the price of more risks, which have to be compensated in turn by a whole chain of business/logistic/human/technical processes and mechanisms.