> Since money is fungible (a dollar is a dollar no matter from which hand it comes from or pocket it goes into), it doesn't matter.
It does matter, not because those recipients will necessarily receive more money as a result, but because they will become beneficiaries of Amendment 64 and the (legal) marijuana trade.
In the case of the schools, this was intentional - in ten years, if someone wants to repeal Amendment 64, they either (1) have to come up with $40MM elsewhere in the budget, or (2) have to face criticism that they are "cutting the public school budget"[0].
The intent of the tax (alongside the stipulation that it be spent on education) was not to raise money for schools; it was to make opposition to the measure less palatable.
[0] Don't underestimate the power of PTAs - in fact, it's the PTAs in rich areas that originally lobbied in the late 1970s to repeal just one part of the Rockefeller drug laws in New York (possession of marijuana under 27 grams). Their children were being convicted of minor possession, and due to the mandatory minimum sentences, judges were powerless to do anything but sentence them to prison.
Of course, these same rich parents did not view (e.g.) the crack cocaine vs. power cocaine sentencing disparity as a problem, so those laws remained in effect.