The TTC's stubborn attitude toward regional integration is about 30 years out of date. Up until 1980, the vast majority of jobs, population and growth took place within the 416 and the TTC was free to operate as a hermetically-sealed transit agency at complete odds to the region around it. Since then, more than half the people in the GTA have come to live in the 905 and I'm probably sure that the proportion of jobs is either there already, or closing in fast. The GTA's biggest transit problem is that there is very little regional integration and apart from downtown-focused GO services (with some piecemeal bus services whizzing around 905 highways to far-flung educational institutions), there is no real regional transit operator. There has been some success at amalgamating three tiny transit agencies into moderately sized ones like YRT (you can forget about Durham transit) but that is really only an asset for York Region, and baby steps compared to what's needed for full regional integration and planning coordination.
Now, Metrolinx isn't perfect, but at least it's not resistant to regional initiatives like the TTC has been. This sort of mentality is not just out of date, it's toxic for public transit growth given the regional circumstances that we find ourselves in.