It could just be that Hazel was able to galvanize a city-wide identity with her strong personality. Mississauga was also rapidly building out at the same time immigrants poured into Canada in the 70s/80s and to them it was all "Toronto" anyway.
Right on the first point. However, there has also been a fair bit of institution-building, hasn't there? For a long time, there have been "Mississauga" hockey teams and high schools and all the rest of it, no?
On the second point, that's equally true of Vaughan.
Also, Vaughan doesn't try to create an identity either. For example, there's a "Concord/Thornhill Sports Park", and even a fancy "Welcome to Woodbridge" sign eastbound on 7 at Weston Rd.
Right. Thornhill, Woodbridge, Kleinburg are still pretty distinct. In fact, they have almost nothing to do with each other.
I suspect one of the biggest differences between those and Mississauga, though, has to do with geographical contiguity. There is lots of space between Thornhill, Woodbridge, Kleinburg. (Less so Maple.) They don't exactly bleed into each other -- I mean, Kleinburg is a little town way out in the boonies, from the perspective of a Thornhiller.
So Vaughan is really a collection of distinct locations. Some of the space in between them is starting to get filled in with residential -- specifically, Maple and Concord are kind of expanding into extensions of Woodbridge and Thornhill, respectively, and maybe these will eventually even bleed into each other. But it's a long way off.
Isn't Mississauga kind of more filled in, as you move from Streetsville to Port Credit and so on?