Mr. Speaker, it is because they had not thought of it yet.
Basically, for some years now, the government has been trying to pit two visions against each other on the assumption that its own would win. It is not as silly as it sounds, because political games can pay off in Canada if they involve attacking Quebec's unique values. However, that will not work. The next government of Quebec is very likely to be a sovereignist government. The current Premier of Quebec was once a sovereignist, and only God knows what the wisdom of old age will show him one day.
Then, the government saw an opportunity to tackle this issue head on and kill multiple birds with one stone. It could crush secularism and, in doing so, crush protection for the French language and lots of other things by centralizing power right off the bat, in a permanent and systematic way, in the hands of the morally superior federal government, of course.