Why haven't the 3 Canadian territories become provinces?

Question

They're governed differently because so few people live in the far north, and so much relies on federal money anyway. A territory would need hundreds of thousands more residents and a much bigger economic base in order to justify the effort of amending the Constitution to make it a province.

The Quora answer overhead doesn't fully answer the titled question. If these territories' populations and GDPs per capita are too scant, then why

1. wasn't one territory created over these three's areas? I know that Nunavut split from NT on April 1 1999 for demographic reasons, but why's ethnic homogeneity so important?

2. weren't these territories fused with provinces (e.g., YT into BC)?

Source: The Canadian Justice System: An Overview (2017 4 ed). p. 18 Top.

TERRITORIAL GOVERNMENT POWERS

Yukon. Northwest Territories and Nunavut have a different legal status than the provinces. Though the powers the territorial governments exercise are very similar to provincial powers, there are differences, even among the three territories. Rather than receiving constitutionally protected realms of power, all three terri-tories are created by federal statutes, Yukon Act, Northwest Territories Act and Nunavut Act respectively. Section 18 of the Yukon Act, section 16 of the North- west Territories Act and section 23 of the Nunavut Act, list powers that can be exercised by the territorial governments (called Legislative Assemblies in Yukon and Nunavut, and Council in Northwest Territories). These lists borrow their wording directly from the powers listed for provinces in sections 92 and 93 of the Constitution Act, 1867, but also add some unique features. Because they are bestowed by federal statute, powers could be taken away or added by the federal government without going through the complex amending formula process that would be required to change the constitutionally protected powers of provinces.
  All three territories have some law-making powers that have not been specif-ically addressed in the constitutionally assigned powers granted to provinces. For example, each territory can legislate in relation to "intoxicants" (because of clause in the Yukon Act, clause 23(I)(p) in the Nunavut Actand section 49 in the Northwest Territories Act). The Northwest Territories and Yukon have both been granted a power to levy a tax on furs, through clause in the Northwest Territories Act and clause 18(l)(g) in the Yukon Act. This issue is not directly addressed in the Nunavut Act. The Northwest Territo-ries are granted a unique law-making power in relation to the herding of reindeer in section 45 of their Act, while Nunavut's government has responsibility over the preservation of the Inuktitut language due to clause 23(1)(n) in their statute. Yukon and the Northwest Territories have an enviable power. like that granted to the provinces in section 92A of the Constitution Act, 1867. to make laws in rela-tion to the exploration and extraction of non-renewable resources (section 19 of both the Yukon Act and Northwest Territories Act), Nunavut has not yet acquired this power through negotiation with the federal government.

Answer 1

For your first question, as usual, the answers are historical in nature and have a lot to do with politics (hence the question being asked here, I suppose!) I'm simplifying a large amount of information; as well, some of the developments were administrative in nature, so I won't discuss them here.

1. Originally, all the current territories, but also including Alberta, Saskatchewan, and most of Manitoba, Ontario and Québec, was part of Rupert's Land (controlled by the Hudson's Bay Company until 1868), which was sold to Canada by the UK for £300,000 in 1870. A very small part of that land was hived off at the time to create Manitoba.

2. British Columbia did not enter Canada until 1871 after negotiations started in 1870, so its boundaries were already defined.

3. The remainder of the Arctic was added to the Northwest Territories in 1880 after the imperial government transferred control to Canada under the Adjacent Territories Order 1880

4. The Gold Rush in the Klondike in 1896 brought in so many people the area that it was separated into its own territorial jurisdiction in 1898, although the area had started to have local government in 1895. Its current boundaries were fixed in 1901.

5. Starting in 1901, major amounts of land north of Ontario and Québec were transferred to those provinces (smaller amounts were transferred in 1874.) The current boundaries were not fixed until 1927.

6. Alberta and Saskatchewan became provinces in 1905 after gaining sufficient population that they merited provincial representation.

7. Regarding Nunavut, it was created because of the implementation of the Nunavut Land Claims Agreement in 1999. Due to the size of the land claim, the land was now effectively separate from the Northwest Territories so it was made its own territory. Ethnic homogeneity was not the goal, but is simply reflective of the demographics (the Arctic is very sparsely populated, largely by First Nations and Inuit peoples.)

TL;DR: The Northwest Territories used to be much larger, but land was transferred to other jurisdictions over the last 150 years. The Yukon was a product of history; Nunavut was a product of land claims settlements.

For your second question, I'm not entirely sure why British Columbia wasn't extended northward. My guess is that the negotiators for the Terms of Union simply ignored the land: British Columbia was the largest province in terms of area at the time, and there was little to attract their interest other than fur trapping. By the time that other provinces got land transfers, the Yukon was already its own territory (and quite a profitable one for the federal government!)