Then again, the entire framework of the Japanese Aiki arts (both DR and Aikido) is flawed in their approach and the effect on the execution of skills can be limiting. The Japanese arts are hamstrung by the training model of Uke / tori. A model, that will forever prevent the development of those deeper skills.
I don't know...I did Judo for a long time before Aikido. I think there is something to be said for actually learning how to do the technique properly before you do randori. You can have all the IS in the world but if you don't do the technique right you're just one step up from the person that is using conventional strength. And before we get to the 'there is no technique' argument....that only seems to happen after the person has spent the last 20 years practicing techniques.
As far as fighting goes...If the method of transmission of kata wasn't effective at a time when you died if you sucked it would have, well...died out. If it's not working today then people are probably not practicing the kata properly. Giving the fact that 'aiki' is lost/hard to find/hidden in plain sight, it would be not be surprising if the proper execution of kata and the proper uke/tori relationship is lost for most.