Re spikes in demand, the article ignores that REST unlike SOAP is cacheable. REST is popular precisely because SOAP has struggled in enterprise as business systems have moved online and the traditional services haven't been able to deal with the traffic.
Re transactions, REST architectures are stateless. But the wider problem illustrated in the article is that enterprise architecture is based on pre-web thinking and uses patterns which are suitable for secure, robust, transactional/stateful, low traffic internal systems (banking, payroll, ticketing etc). This is pretty much the opposite in every way to web architectures - so what good looks like in one is what bad looks like in the other.