I understand how people defend Apple on this but it is a gray area in my opinion because it is a subscription. Apple has nothing to do with the monthly billing because it does not go through the App Store. I fully agree that they should get 30% of the first month but not so sure they have a right to 30% of the ongoing reoccurring billing.
Not Google, Amazon or Facebook. All of them are building new data centers as fast as possible. Although Amazon does have peak data requests such as Black Friday and Prime Day, Google and Facebook probably have pretty steady network demand so it is much easier to bring additional capacity online without disruption. Apple has just released a new high demand service with Beats1 and Apple Music so a little bit of fine tuning is understandable.
Another thing to notice is that all the systems that are down are the huge data services like OS X update, iTunes-U and Mac App Store, etc. It sort of looks like as the system started to fail, they purposely turned off the non-essential huge data services. All the Apple ID, Apple Pay, keychain, iWork, Mail are up. Looks like plan B.
It is probably not a case of too much traffic, but just new untested networks. I'd guess they are making lots of changes to the network infrastructure with all this Apple Music stuff and they probably screwed something up. Designing and managing edge routers, firewalls and load balancers is pretty complicated stuff. A single misconfiguration can produce a cascading accidental ddos, but there is no better 'rubber meets road' load testing scenario then a high demand event....
Articles like this are just trying to glamorize the millennial generation as free from the societal norms of their parents. Every generation had something similar to rebel against normalcy. If the millennials are not buying cars they must have lots of money in their savings account, or maybe they are spending it all on tattoos.