The OP is somewhat correct. Blizzard is too focus on Raids and less focused on the the actual world. They should have brought a couple of new 5 mans, this is something a lot of people have enjoyed in the past. Blizzard has the resources and the money to be able to do more without affecting the raiding experience and still be able to bring out awesome raids. Don't get me wrong, raiding is fun and MOP has to be one of the best Raiding expansions ever.
As someone stated before Timeless Isle is pretty much a way to super fast track your Alts to be able to get into... 'raids' since this is all they are focused on. Proving Grounds is a fantastic feature in the game and a great Challenge. So what does a Non Raider do? just spamm proving grounds with their main? farm the shit outta timeless isle then spamm proving grounds with all their alts? Not much fun for content that will be out for at least 6 months.