There is little correlation between building a subway, and attracting the developments post construction to justify the subway's construction. The Sheppard stubway is a good example of how development was not spurred by the new line, and today, fewer riders use it per day than the King, Queen, or Spadina streetcar lines. It costs the TTC (thus taxpayers) 8 dollars per rider in subsidy to run the Sheppard subway. Not a fiscally responsible way to build transit.
To your point about Scarborough not getting its due, Mayor Miller's Transit City sought to redress years of Scarborough being left behind in transit planning by delivering the Eglinton LRT, Sheppard LRT, and Scarborough Town LRT. We must remember that the main funding for today's Scarborough subway was procured due to the previous administration's efforts, and the fact Scarborough is getting 3 major transit projects in the near future is not really due to any efforts by Ford. If you are indeed from Malvern, your praise of the Mayor should also be tempered by the fact that your area of the city would have received higher order transit if Transit City had not been gutted by Ford. As it stands today, folks in Malvern will still have to slog it to STC in order to access any higher order transit.