To offer another perspective ...
Downtown Markham isn't really any more out of the way than anywhere else that isn't across the street from wherever a given person lives. Public transit runs through it. And if you're in a car there are routes in and out from every direction. For someone living at 16 and Kennedy, or Brimley and Denison, there isn't much of a difference in time or convenience to get to Markville Mall vs DTM. The anchor tenants will come in time. But the retail ones are going to want (I would think) more density in the area before they make the commitment. York and Cineplex moving into this area aren't the same as a retail store that gets a lot of walk-in traffic (i.e., the Apple store).
Things are headed in the right direction. Times Group's "Uptown Markham" to the North will add density -- I believe the one tower currently underway is going to be 28 storeys. Presumably there will be a new commercial building or two in the next 4-6 years. And in the not too distant future we've got the York condos (late 2020?), the York campus (2021), and Gallery Square (2022?-2024) coming online. Will that be enough to attract a big retail player? Hard to know. Even then, perhaps only 25% of the DTM lands will have been developed.
