You're making a valid point, but I think you're exaggerating its importance. The correlation between Ford's 2010 vote and neighbourhood household income does not just hold at the Ward level, it's also true at the Census tract level. Census tracts are small and pretty homogeneous. If Ford got his votes from low-income tracts, then he almost certainly got his votes from low-income people.
We also have individual evidence from opinion polls. Ford's approval rating is highest among people with household income under $20,000.
It's also a pretty convincing hypothesis. Ford is a populist; he LOOKS like a working class striver, even if he's not; and like many populists he says he can make government cheaper, which must sound pretty good if you're poor. And, as somebody else said, he's not gay. Given all that, why wouldn't we expect the poor to vote for him?
Tough news for all you Marxist-Leninists who voted for Miller, but there it is!
If anyone is exaggerating, it is Preville, which is why I'm in the right to call BS. Let's take a look at his thesis:
This [suburban vs urban] narrative doesn’t tell a true story about Toronto. There is a deep divide in the city, but it’s a class-based conflict between haves and have-nots—or, more precisely, between neighbourhoods with improving prospects and neighbourhoods on the decline. And Ford Nation hails largely from the latter.
So he is explicitly rejecting the idea that Ford support hinges on urban vs. suburban lifestyle, and arguing instead that it's a matter of class and race. Even if we accept that there are no significant differences between CT and individual-level data, that data still shows a much stronger effect of driving a car and living in old Toronto vs. the inner suburbs than it does for median income (I assume you're talking about the Taylor study referenced in the Preville article). Yes, income is significant. It's part of the picture, but not the full picture. It certainly doesn't justify jumping to the conclusion that Ford Nation represents the great unwashed masses. What would happen to income if we controlled for being a senior citizen (who I suspect are more likely to support Ford)? Or if we broke it into income cohort. That opinion poll you mention also shows that Ford's support is much higher among people who make over $250,000. Even if income matters, we're a long way from determining how and why it matters.
Another thing that Peville claims is that visible minorities are more likely to support Ford. He even backs up his claim with an implicit suggestion that we should see Anthony Smith (Ford's now murdered crack dealer) as evidence of Ford's appeal in the minority community (a claim that's not only ridiculous in terms of its logic, but also leaves this racist aftertaste of a white person lumping all minorities into the same group with a dark-skinned crack dealer). I haven't seen any CT-level analysis on race and Ford support. And that opinion poll shows that people of non-European ethnicity are less likely than the average Torontonian to support Ford.
Finally, back to the census tract data. Ford got about 50% of the vote, with 50% of the turnout. Meaning on average, only 25% of eligible voters (a smaller group than would be captured by the census because of non-citizens and other ineligible voters). Even in the ridings Ford won by a landslide, the number of voters was probably still less than half the adult population. And when you think of the average suburban block (detached houses in the center, high-rise apartments at the intersections in the corners), there's still a lot of possibility that Ford voters are not representative of the area in which they live.
Anyway, this article is just another example of non-Ford supporters coming up with simplistic, stereotyped, reified conceptions of Ford Nation (in this case as the great unwashed masses, the have-nots driven by bitterness and resentment). I don't mean to claim that raising inequality is not a problem. It is. But let's deal with it in a more serious way, and not see the actual have-nots in the city through the lens of Rob Ford.
EDIT: Let me put it this way. The median income in the 905 is higher than the 416 (a lot higher in some cases), but I suspect Ford would have won those areas too if they were able to vote in Toronto's 2010 mayoral election.