The only thing forced by the share-alike provision is that the downstreamer could be forced to use a cc license for his work, which realistically means nothing because he cannot grant additional rights to my work.  viz he could not grant commercial publishing rights to his work while it contained more than fair use excerpts from my material.  He cannot break my cc grants in any significant way that I can see, and I have ethical qualms about trying to force others to my values regarding their works independent of me.

There is a huge difference between code (at least that which is compiled) and text.  In textual literary matter the meaning and value is only in and as text.  In code the binary derivative work is useful (at least on approprate architectures) in and of itself, hence the derivative works provisions of the GPL.  I don't see substantial value for that in textual matter.

As for non-commercial, that means what it says; it does not preclude the author from selling any (non-exclusive) commercial rights_ if someone wants to reproduce other than in a cc/nc manner they need to contact the author to buy those rights.

In q quick glance through of the CC site I didn't see much about a commercial variation.  Do you have a link, or could you explain it a little more?