I actually think it has to do with the peculiar nature of US political history. I wish I could remember the term for it, but back when I was doing my poly sci BA one of my profs started explaining a funny little thing that one of your Founders (Madison, maybe?) did. Because of the context of the Revolution, and the emphasis on checks and balances, the Parliamentary system was discarded for the...
thing... that you folks have.
But it went well beyond that. It was intentionally designed to oppose itself, stop up, and not get anything done. Seriously. That was the actual goal. Can't have a tyrannical government if the government can't actually do anything, right?
Parliamentary systems don't have that problem. We have
other problems, but not those ones. The biggie is that the executive and legislative branches are fused, not separated (something
literally called
Responsible Government) which A) requires that the executive is responsible to the legislature and B) means the legislature doesn't block the executive from governing. Also, we get to have more than two parties, which creates a diversity of views in government and provides a check on the larger parties. Hell, big parties have come and gone entirely in just the past few years. There's churn rather than the entrenching of power structures.
(Also, as an aside, what the hell is with that two party thing anyway? There's no law saying there can only be two. I have a degree in political science/history and another in law, and I
still don't know what the deal is with that.)
More recently, and not foundational to the systems themselves, there have been more changes made that differ between the US and other places. Political donations, for example. There are strict limits up here; not in the US. Gerrymandering. Doesn't happen in Canada; happens all the time in the US. Supreme Court appointments. The Supreme Court is apolitical and extremely well-regarded by normal people in Canada; need I say anything about the USSC?
And so on, and so on.
Point being, in both countries, politicians want votes. In the US, for historical reasons, the way to make that happen is very different from how it's done in Canada (or the UK, or...). In the US, you make companies happy, they dump cash into your campaign, you win the election. In Canada, because the emphasis is on party rather than on individual MP due to our governmental structure, and because companies can't dump cash on you because of policy, that doesn't work. At all. So there's no incentive, for example, to buddy up to telecom corporations by scuttling net neutrality.
Again, we have different problems (the centralization of power in the PMO and the incentive for
parties rather than individuals to chummy up with corporations, for example), but I'd submit that they aren't as bad.
It's a structural problem. You got fucked back in 1776 when a bunch of Virginians decided to pick up muskets instead of pens. They overreacted to their problem and set up a busted system. "Don't Tread On Me" is a good slogan for 18th century Americans; "Don't Set Up Political Incentives To Do Evil" is a better one for 21st century Americans.