because Verlen used too much Kevlar, both in his boats and in his paddles.
There were lots of trials of Kevlar paddles back around 1980, and they were all failures. It's a light, tough fiber, but lacks compression strength, and so tends to "scrunch" on the non-power paddle face, and also doesn't take rock strikes as well as glass or carbon.
Canoe / Kayak Anchors
Heel and Pegpads™