Well I suppose I understand what you're saying but I think it's far too early to be coming to conclusions like that. For one we have no idea how long the dungeons are, how much sp they give, or, really, anything about them at all aside from entry requirements.
Also I think content like this would benefit greatly from an improved party search mechanic. There aren't really that few people in the proper rank range, it's just not easy to find them walking down the street. Again though, we need to just wait and see. As it is we're basically arguing which way the wind is blowing on the other side of the world.