I don't think its useful to look at limiting languages in terms of 'resources' available for providing Wikimedia projects. As Aphaia and Gerard point out, what we're dealing with is volunteer resources - which cost the Foundation nothing and can't be required or redirected in any case.
What is more key, I think, is a question like this: What is the minimum size of an active community that can reasonably be expected to produce articles of a basic degree of quality?
In this case, the active community would be drawn first from among literate speakers. Then from the literate, you take those who have regular computer access. From those, you find the few who are willing to devote time to a wiki collaborative effort. If you start with a small literate community, or a large literate community with low levels of Internet access then you will necessary have a small Wiki community.
A small Wiki community is a reliable indicator of two things: Limited quality, and limited readership.
Neither of those two things satisfy the goals of Wikimedia.
~Nathan