No, it's not an irrational fanboy problem, it is a money problem. If I could afford to sell out of Canon and replace all my Canon gear with Nikon, then I'd do it in a heart beat. But I can't. And I suspect the same is true for many others. We're all effectively held hostage by Canon so we're pretty much at the mercy of whatever Canon decides to deliver to us. Some of us are angry that Canon is lagging so far behind in sensor development when compared with what Nikon and Sony are doing, some of us aren't. And that's how Canon stays #1, just like a drug dealer, get 'em when they're "young" and you've got them for life.
Are you sure you can't afford to? Is that because the equivalent Nikon gear is more expensive? I completely jumped ship from Pentax to Canon a couple of years ago, selling all my equipment in the process. The only item where I clearly lost money was the camera body I had bought new at full price (I don't really consider it a loss anyway because I got a lot of use out of it while I owned it); everything else I sold for more-or-less what I paid for it (a bit less if I had bought it new, sometimes more if I had bought it used). I doubt that's unusual.
As for Canon the drug dealer, most of Canon's sales are of Rebels (and below), and most such customers probably stick to their Rebels and don't move either up or sideways. Those who feel trapped or who suffer from sensor envy are more likely the minority who are enthusiasts, and these days it's fairly easy for them to avoid Canon's evil plot (if that's what it is) by buying a mirrorless camera with a Sony sensor and using their Canon lenses on that....