Because that's a conspiracy theory.
You've offered no evidence of 'false pretenses' and not illustrated any rational benefit for Western powers. Just the opposite - SNC Lavalin (Montreal) and others lost lucrative contracts.
And this "As such the US, Canada, France, UK, and Italy all have the blood of slaves on their hands in Libya" - is completely ridiculous. It's reddit-rhetoric, essentially to blame one 3rd party for incidental actions in some other area, at the same time not holding primary antagonists accountable for their actions. Like blaming the US for bombing Japan ... after Japan spent 35 years invading, mass murdering, mass raping, looting, firebombing, all sorts of countries, 100's of millions of people displaced or killed in SE Asia ... and then attacked the US.
Gaddifi, a known antagonist who blew up a civilian airliner, publicly stated he was going to commit mass murder in E. Libya. That's a legitimate pretense.
Did the Western powers stretch their mandate by continuing to support forces in E. Libya after NATO destroyed advancing columns? Yes, but that's completely within the boundaries or rational action.
Libyans did most of their own fighting, NATO provided air cover and Intel, and other ME forces (i.e. Qatar etc.) chose to work on the ground. Their choice.
That some rebels, who were temporarily victorious were able to set up bank accounts for clearing payments is not suspicious. That would be the #1 thing they, and we, would want them to do. To the extent that they seem like 'the best choice out of bad options, good enough to lead the country', then it's reasonable that other countries recognize the new leadership. It's each countries choice to do that.
"Instead of installing peacekeepers" ... this is not what peacekeepers do.
I'm also Canadian, and was in the Armed Forces, and am deeply acquainted with this type of mission.
The notion of 'peacekeeping' is misunderstood by the general public to the point of dangerous naivete.
'Blue Helmet' style peacekeepers can generally only work in situation where most parties have agreed to end hostilities, and usually where the forces aren't very powerful or advanced. They are observers, and generally unable to project force in a manner that would keep the situation under wraps. Literally they observe, make notes and generally don't have the established rules of engagement (or force) to be able to do anything material.
Only 'vastly more powerful application of force' can forcibly 'keep the peace' between antagonizing powers. The US occupation of Iraq, for example, would be truly what we think of as a 'peace keeping operation'. The chaos and tumult and even low-grade violence that was common there is normal and expected. That's what 'actual peacekeeping' looks like.
Because of the reluctance of Western powers to put any physical presence (i.e. 'boots on the ground') they opted to support a group that could somehow, possibly form enough of a coalition to keep the situation intact.
... but because of how Gaddafi adeptly managed to keep the tribes fragmented, at each other's throats, disunited and feckless ... there was nothing reproaching a legitimate political opposition or even coalition that could provide leadership.
And so you have what you have today, which is probably worse than what you have in Iraq.
Paradoxically - Libya would have been much easier to occupy than Iraq. They don't share a border with powerful antagonists (Syria, Iran), they don't have individually powerful groups, they don't have deep infiltration of more radical elements (Al Queda, ISIS etc. - although that could happen) and there's no way for them to be supplied. Algeria, Tunisia and Egypt are not going to allow shenanigans across their borders. The desert route is too long and the areas to the south are hostile.
A NATO-led coalition occupation might have been 'the most ideal of a list of bad options', but it would have to have been on a large scale, there would have been low-grade violence on the news, and garrisons could be expected to be there for decades. Only the US has the ability to really do that, but neither they nor most other advanced nations have the appetite for it.