GW2 doesn't have instanced raids, or the elite zones of GW1, and little gear treadmilling. That's what they're talking about. They have been conditioned by the WoW dominated decade of modern MMOs to equate a gear treadmill that you participate in via raids with endgame content. While I wouldn't be shocked to see either a return of elite zones or instanced raids added in GW2 lifetime, GW2 is never going to quite fulfill the stereotypical end game model, especially since they've ruled out a gear treadmill.
GW2's "end game" breaks pretty decisively with the old model. First, consider WvW. For all the complaining we do, WvW is probably the best realm vs realm content out there. There is a very large, dedicated community that focuses on it.
Second, the Living Story means that even though you've hit level cap and finished your personal story, there's continuously new story stuff to be doing. People don't consider this "end game" because the story in MMOs is traditionally done during levelling and is static. Since it's not ongoing, it's not endgame. In gw2, even max level characters are constantly participating.
Finally, there is high level pve content. High level fractals are appropriately challenging to be considered end game, and some of the open world bosses are also in that category. Because fractals are limited to 5 man groups, and the larger open world content is essentially public, there's a group of players that isn't completely satisfied with end-game pve.
Of course, there's also spvp. However, without a full on ladder type system, I don't think spvp is well situated to be a major end game draw for the majority of players.
The point is, end game in GW2 breaks with the classic end game model, so at first glance, some people are going to look at it and conclude there isn't any. They're going to see things that can be participated in equally by casuals, or even non-80's, and conclude there is nothing to do once you get beyond that level. But in reality, between doing the living story updates, running high level fractals or other dungeons, and doing some WvW, there's really plenty for even the hardcore players I play with to do. The fact that we can bring along our more casual friends sometimes doesn't negate that.