It's neither semantics or pedantry. It's a matter of gov't dealing with the unintended consequenmces of it's actions (or, in this case, it's ability to cave in to a vocal constituency).
Whether or not the pot in question is restricted solely to medical purposes, the Canadian gov't is now the de facto largest distributor of narcotics in Canada (or at least it has the potential to be). The fact that someone else is growing it under contract makes no difference --- if tomorrow, the Candian gov't decided cocaine had the same therauetic effect (and potential for profit), it would get into the cocaine business as quickly as it could. However, cocaine still has bad P.R. attached to it, unlike pot.
This is not a government's job.
Whenever a government condones or expedites the public's penchant for getting high, whether it is medical marijuana or a needle-exchange program, and does so under the aegis of "protecting the public" or "administering to the public need", it is, in fact, trying to muscle in on a criminal activity. It does not do so because the public wants it, it does so because the government has it's own motive: i.e. profit.
From what I've heard (I have several friends in Toronto and Calgary), the government-issue pot is absolutely awful, and so, those who want it find alternate supplies. The criminal element is still profiting from a so-called "legal" commodity, probably more so now since the government contractor cannot even grow pot properly.
If the intention of the Canadian government was to profit from a previously illegal trade, and I believe it was, it has failed miserably. If the intention of the Canadian government was to pander to a small, but vocal, minority, it has done so to the potential detriment of the rest of the nation.
The same arguments are made here in the United States, the difference is that we haven't (yet) totally lost our minds on the subject of government involvement in the drug trade.
The de-criminalizing of previously-illegal substances and activities, even when narrowly defined and rigidly controlled, does not remove the criminal element, nor is it good public policy. In this country, Prohibition was finally repealed because the government needed tax revenue, not because there was a major hue and cry for alcohol(the fact that there was, was simply convenient). The U.S. government may pretend otherwise, but it really only sought to profit from an illegal activity. Why should Al Capone have made all the money?
The Canadian government is doing the same thing --- hiding it's true intentions behind "doing the public will".
The number of people approved for legal medical pot is a tiny proportion of the users in Canada. It is misleading to imply that the black market in pot still exists because of people who aren't satisfied with the gov't produced stuff. Even if they were perfectly satisfied with it, there would still be a huge demand for it for recreational purposes.
Decriminalization is about removing the worst of the consequences for users. I don't think anybody expects it to have any effect on criminality on the production side. I certainly don't. I do think it's a good thing that people won't have their lives ruined over a minor pot possession bust.
As to the government's motivation for legalizing it, well they haven't proposed doing that. The legalization of medicinal pot is not going to produce any major revenues for the gov't. In fact, the main reason they did it is because of court decisions that were on the verge of completely striking down the laws against possession due to the lack of provision for medical use. Having dealt with that they can get back to making the laws they see fit to. As it happens, decriminalization for possession of small amounts enjoys widespread support in the Canadian public, for just the reason that I've mentioned.
Well, that's my point of view, anyway. Yours obviously differs.