It's obviously a complex issue, and it's hard to find cause and effect relationships in all of this.
However, there's a well-known phenomenon in the sociology of science called the Matthew effect. Basically, the scientists or the institutions with the biggest amount of symbolic capital and prestige will receive even more, regardless of the intrinsic quality of it all. If two scientists discover the same thing at the same time, the discovery will most likely be attributed to the one who already has an enormous amount of capital. We know this to be one of the natural effects, say, of the scientific system, that is, giving more to those who already have it.
If future funding is based on past funding, that obviously leads to the concentration of funds, largely in the hands of researchers affiliated with U15 Canada.