After a great deal of training in the system it makes more sense to refer to the Dentokan style as simply Jujutsu. Mainline Hakkoryu and KoKoDo seems to explore the concept of aiki in a way Dentokan does not. If you sat down and had a conversation about aiki with Hobbs sensei you would be presented with a viewpoint more in line with Karate-Do or Judo.
I've come to prefer the "mechanical" approach to aiki myself. I was initially caught up in the deep aiki/ip training concepts, but I find myself more interested in taking the other path. Kick them in the nuts, mochi mawari the crap out of their wrist and call it a day.
Well I've only had direct training from Hobbs once, at a seminar two years ago, but one of my shihans is a very senior ranking member of Dentokan, and often has anecdotes of his times training with Hobbs Sensei, so I think his teaching is a fairly good representation of Hobbs'. I would be inclined to agree based on my training that aiki is not really taught. However, as you mentioned Kokodo and Hakkoryu explore aiki in more depth and so I think it can be found in Dentokan, but you have to discover it for yourself. There's nothing wrong with having a strong foundation in Jujutsu and I like my training in Dentokan aiki-jujutsu and its emphasis on the Jujutsu waza. However, for me the martial arts are a path of learning and self-development, and I want to continue to pursue this path and not just tread water. Aiki, I believe is part of the path I have chosen through the martial arts and so therefore I want to learn how to develop it.