Royalties are paid for the franchise to extract resources owned by “the people” (or the Crown, or the Soviet, whatever). They are a cost of doing business for the miner. If a company wants a resource, it pays for it — same as if it needs office space, it pays for that.
We all know what a tax is.
Royalties are a cost of doing business, so are taxes.
I'm not saying that Canadians don't deserve to be paid for their oil. However, increasing the percentage of existing royalties is exactly the same as taxing oil production in this instance, and has exactly the same effect.
When the government decides to increase the revenues they receive from business, that is usually called increasing taxes. However, in this case, since their is an existing royalty they can just increase it and say that they didn't raise taxes even though the effect is exactly the same.
In this case, it's just arguing semantics. In either case the government is talking abut taking a larger chunk of revenues.