Maybe... my personal experience is that soft alone isn't all that strong. I'm quite soft, and it generally works well, even with partners who are attacking fairly strongly, but there's also a clear point where my softness will just collapse under the pressure so to say, if the pressure is high enough.
In daily life this works very well for me, i generally feel very free and comfortable in my own body, which is a wonderful feeling. But for dealing with physical attacks above a certain level of intensity it doesn't always work.
Hmm. I just realized that I might be thinking about softness in a different context than you guys. If were talking about how soft or strong a technique feels to uke...well I still wouldn't know what to answer. The best techniques I've felt didn't feel either soft nor strong. I couldn't feel them at all.