kEiThZ
Superstar
This frustrates me too. Unfortunately, I've also come to recognize that rapid transit expansion is almost never about improving travel or capacity constraints, and almost always about opening up real estate development.
If you can stimulate real estate development without a rapid transit line, then a rapid transit line will go on the back burner (see DRL).
That's because, it's becoming the only way to fund transit expansion. There's no business case for a line that won't spur much new growth and bring in more tax revenue. If there was more funding for subways, you wouldn't have this situation.
But with regards to Vaughan, consider the alternatives: 1) no subway at all beyond Downsview 2) Sprawling development at VCC without a subway.
Ideally, development plans would be developed with transit in mind. Why are people begrudging Vaughan for doing things right? It doesn't have to be a zero-sum fight. Places like Vaughan should be getting subways when possible. And the core should also be getting the infrastructure that it needs (eg. DRL).