That may be what the article says, but it's not actually true. What is true is that ENB can only grow at a rapid rate because of investor confidence and new issues. This however is true of every pipeline company and REITs, all of which use a similar model. Hell, this business model goes all the way back to canals in the 18th century.
It works like this: ENB has pipelines which pay dividends to existing shareholders. When it wants to build a new pipeline because it feels that it will be accretive, it issues shares to fund the new pipeline. The new shareholders provide the capital, and provided that the project actually is accretive, old shareholders benefit as well. Shareholders should worry if ENB's growth is not proving accretive on a per share basis, but that has not been the case so far. Some day, of course, ENB will stop growing rapidly, as there will be no more need for new oil and gas pipelines. Then its business will look a lot more like ENF, which has tons of earnings, since it's not spending much on growth. Instead, it just pays out the proceeds from its mature assets. However, right now, there is huge demand for new oil and natural gas infrastructure to serve the shale complex. How fast ENB grows now (provided it doesn't overstretch its balance sheet or dilute excessively) will determine how much it can pay out a decade or two from now, when the assets right now will still have decades left in service, but there will be less need for new pipelines.