This webinar is an excellent overview regarding current DCI design challenges. I would highly recommend to watch it for anyone working in the networking and datacenter space. Sober networkers should watch it thoughtfully at least two times. L2 DCI fans should watch it once in a month, until reaching a solid grasp.
If only life would be as easy as that ;) Most people prefer to be blissfully ignorant of the infrastructure supporting their business, while at the same time pretending they know an awful lot about other people's jobs (see also: Dunning-Kruger effect)