Actually, Daito ryu was not extremely popular at the turn of the 20th century because it involved cultural elements that were commonplace at the time at all. It was popular because it gave students at that time the feeling that they were, in fact, participating in bygone traditions and culture of the preceding era.
So yeah, I think Ueshiba was in fact studying / attempting to emulate a culture that was not entirely his own. So for those of you who want to try to follow in his footsteps, maybe you should consider that!
Well, there was a general tend towards westernization in Meiji - but I can't think of any of Sokaku Takeda's students who were actively or primarily interested in the cultural elements. In fact, Sokaku taught mostly short workshops with people who were primarily interested in the practical martial elements.
In any case, I think that if people think really think that they are learning Japanese culture in Aikido class - then they ought to think again.