There are some very interesting and valid points being made here.
I think that we need to look at which level of Aikido development we are dealing with, when speaking about whether or not one should go "bara bara" or not.
If using the baseball analogy, I would say that no matter what you are dealing with in terms of batting, you still need to learn to swing the bat properly. There are different ways of swinging the bat, but in terms of physically teaching your body to get a good fundamental form, I think most would agree that it is better to let one instructor teach you how to stand, grip, observe and swing. If you have three different batting coaches teaching you to begin with, it will obviously get pretty confusing. Saito Sensei would often use the baseball analogy of having to learn how to throw and catch the ball before actually getting into the game.
Once you have established a good outer form, then of course you should be open to what may be found from other sources.
And then in regard to the spiritual aspects of Aikido: Isoyama Shihan and Inagaki Shihan are both very adamant in making the point that if we stay stuck in the physical realm of Aikido without looking deeper into the spiritual aspects, then O-Sensei's great efforts will be put to waste. But we do need a proper physical form to create the vessel for which the spiritual aspects can be contained.
I understand the need to get the form "right" before being involved in more open practice - however research is showing that the earlier you start training people with these methods, the better your learning in the long run - the initial learning is apparently slower and makes parents, athletes, administrators, and coaches a little worried at the initially slow progress, but in the long run - the skills and performances are better.
I don't have access to academic journals (well, not easily), but those who do can use Vickers's work as a starting point to review decision training literature.
As in my earlier post - unlike most aikido instruction, there's often money or medals riding on the robustness of an athlete's sports skills under duress, and sports coaches generally tend to pay attention to the outcomes of modern research, whereas most (but not all) martial arts seem to dwell in the past glory of their founders and fail to do the "research" needed to advance the art. As a coach, I consider myself to have failed if the athletes can't do more than I could when I was competing.
If only martial arts instructors "got" this... Some do, but I doubt all do.