Hoffman writes, "People working from the first principles of the free software movement or the definition of open source software, like me, will never accept non-commercial licensing as 'free' or 'open,' because it limits the use and redistribution of the work." No it doesn't. They can use and redistribute the work all they want. The one thing they cannot do is block access to it by charging for it.
It is certainly not true that "the one thing" prohibited by a non-commercial license is to "block access to it by charging for it." Or if it is true, that's a much narrower interpretation of "non-commercial" than is generally used. My sense, first of all, is that none of this is really settled case law; secondly, last I checked I wasn't a lawyer anyhow. But non-commercial use would generally constrain my ability to use the resources as part of a business. What if I'm running a for-profit day care center? Or if I'm an education consultant paid by public schools? What if I wanted to use the resources as part of the research to formulate a business plan? What if I'm a consultant with a free web site that advertises my services, could I post the resources at no charge to draw traffic to my site (which is, technically, entirely an advertisement for my commercial services?
Also, what if I want to sell a printed or electronic version of the resource which retains the original license, thus allowing further redistribution at no cost, not "blocking access" at all? Or to cite the example from the declaration's FAQ:
For example, is it your goal to forbid a for-profit publisher in a developing country from printing copies of your materials and distributing them there?
In case it is not clear, my interpretation, and I think the common interpretation of "non-commercial" disallows all of the above, so there is far more than one thing prohibited by those licenses.