是地点状语从句：

The attacks on ambition are many and come from various angles; Its public defenders are few and unimpressive （主句）where they are not extremely unattractive.（地点状语从句）

地点状语的字面意思：在它们不是非常不吸引人的地方，......

可以引申为条件含义：只要它们不是非常不引人注目，...