No one has ever accused me of not being heard. And the guitarist whose solo can blend out my bass playing in listeners' attention has yet to be born. It's the thing I always hear at auditions: "Wow, you really make a difference in our sound." Not everybody likes that though, but enough people do.
And there is one great Sting quote about the subtle power of bass and that is: "If the band plays a chord, I get to determine with what I play whether the listener hears it as A minor or C major." Right on. Guitarists tend to be utterly confounded by this.