In aikido we do not train muscle you know..
The "machines" to train ourselves with are "me" and "uke"
With "me" and with "uke" we still want to train tomorrow Don't we?
So there is no use for destructive force in the dojo.
OK, poor material will couse you trouble.
BUT:In aikido the basic idea is to exercise and use your technique with your "fingertips"
In other words, to control and move your opponent with NO strength..
Then; what is the use of having a very heavy duty stick (or bokken) if you are studying movements?
Isn't it better to use "brittle" instruments?
So we do not learn to gain too much "power" from our trainig weapons?