Thank you all for you responses. My question was not meant to imply that you should not go outside aikido...it really was to ask why?
I didn't. "Outside" came to me, because my teachers invited it in. They have been as public as they are likely to be about their own reasons, so I'm not going to speculate.
Writers are always told to read widely. Read the genres and authors you like, but also the ones you don't, if only enough to understand why you don't like them. Every writer I know has enough books to stock a small library, and a to be read stack that threatens to overwhelm their reading chair.
This is the same idea. Every teacher (and every art) focuses on a different piece of the elephant. There is much value in seeing the other pieces, even if your primary attention remains on a single teacher's approach.
As for lemmings, well... I think there's been plenty of vitriol on both sides, as well as within some of the factions. Certainly the Daito Ryu - Aikido debate is very much like an ongoing family feud, with both sides arguing about who Grandpapa Sokaku (Or Papa Morihei) loved best. In all the sound and fury, it's easy to lose sight of the fact that we really are all branches of the same family, and have a lot to learn from each other.