Well that pretty much mirrors my perspective. I see a long line of tradition and teachers whose relevance to my own study and progress is defined by my distance in time from them. Nariyama, Tomiki, Ueshiba, Takeda, his teachers - a particular name change having no importance - but I am happy to call it Aikido. I think when we talk about a legacy of a particular man we talk about his contribution to the whole and not what he did not pass on. For that reason I rebel against the idea that there is a lost Ueshiba M. legacy.
... and I am opposite in my conclusion. I think O Sensei left a legacy because we have so many references to O Sensei (videos, books, interviews and the like). There is plenty of material from the man, it's just that we (as aikido people) cannot replicate his accomplishments with success. That's part of why I asked Cliff his opinion of legacy. Nobody played baseball like Ted Williams, yet no one would claim that he did not leave a legacy of accomplishments cherished in baseball. Yet we continue to play baseball... If we are going to define legacy as an education passed generationally, I think we are basically claiming that no one
in aikido has ever successfully passed on aikido - like a copy of a copy until the quality is degraded... If no one ever got the whole enchilada, then they could not have passed down the whole enchilada.
Some of this is word-smithing as we use "legacy." If our beef is that O Sensei didn't teach it, then there is no way we can also say Doshu taught it (because O Sensei didn't teach it to him). So it seems to reason that Doshu also would not have a legacy. Now if "legacy" is just a pedagogy, everyone should have a legacy because we all have our own teaching systems.
In answer to Cliff's question, I like the argument of outside sources that also trained aiki because it does show other models of education. It thinks it's important to note that other models did exert more influence over who trained and who "got it". While a harsher truth for those training, maybe not so dishonest as to imply everyone training will "get it" if you just train long enough...
For me, legacy is a softer term that implies a lasting impact. For me, this let's me both enjoy the profound impact O Sensei had on aikido and also what The Splendid Splinter did in professional baseball. In both cases, I understand that there will never be another one as I enjoy something bigger than either one.