I dont get it either. every mmo should have class/profession system so they can play of each other roles
Its' made for casuals and they forgot how gw really works with professions. I really hated the fact when they announced that they wouldnt have a dedicated monk and that made me realize gw2 is for casuals. Gw2 can rot for all I care, when they decided to do a 180.
Classes are not the same, they have unique skills, playstyle, weapons and effects. And in fact there are roles for raids -> healers, tanks, dps, kiters, mesmers with portals and more depending on the raid mechanic.
What they wanna do is provide the ability for more classes to cover different roles in instanced content. Im not gonna say gw2 is perfect, but its x10 time harder to understand and play it at a good level than gw1. So appart of doing story and some random stuff, i dont see the hardcore pve and pvp being casual at all.
A lot of people have a missconception about gw2 based on what the game had when it came out in 2012. But that was long gone, the game has change a lot, with horizontal progression, specializations, raids, more builds/traits and much more.