Yet another poorly researched article.

"tens of thousands of people who are moving there...have no place to walk the dog or read on a park bench."

Roundhouse Park. Canoe Landing. Coronation Park. Garrison Common. Little Norway Park. Toronto Music Garden. HTO Park. HTO Park West. Rees Street Park. Ann Tindal Park. Fort York Blvd has many places to "read on a park bench". Many condo and office towers have their own outdoor spaces. The Toronto Islands are a ferry ride away.

"when authorities were expanding Toronto Pearson International Airport, they failed to put in a rail link, or even leave space for one... they couldn’t just lay track to the airport from a nearby rail line"

They did leave space for a rail terminal. Any rail link between Pearson and the rail line would be on tall pillars because of the existing roads and ramps, not because of the new terminal. 

The Yonge Subway wouldn't be the problem it is today if other subway lines were built.