I was going to write a post as to why Greenlanders might not want to be forced to be US citizens, but it is as obvious as why you shouldn’t stab yourself in the face with a fork. So I’ll restrict myself to some highlights.
The residents are mostly Inuit. The USA does not have a good history for dealing with indigenous people; this is still the case with ICE picking up native Americans for deportation. I think they can expect to be ‘resettled’ somewhere ‘for their own good’.
As a socially progressive nation, having US values imposed will come as an unpleasant shock. Greenland has free healthcare, whereas in the US, 1.3 million people are rationing their insulin because of the cost and nearly 100,000 people a year in the USA because they cannot afford the insulin they need.
Greenland has a progressive education system. While the US citizen (or their parents) pays between $10,000 and $60,000 per year, the Greenland citizen pays nothing for their education and gets a grant for accommodation expenses.
Greenland will either become a state, or, more likely because of its low population, be absorbed under some other structure. Instead of having its own government and laws, these will be swept away as US federal laws take their place. For example, as a part of Europe the death penalty is forbidden; under US law it is not. Oh, and Scandinavian countries have the most reformed prison systems in the world, the USA amongst the worst.
There has been one mass shooting in Greenland; it was 36 years ago. The USA has one every few hours. School shootings are unheard of in Greenland. Actually, they are very rare almost everywhere except the USA.
Greenland permits abortion and it is far from unusual. The anti-abortionists in USA will likely put a stop to that. The Washington Examiner gives that as a good reason for the USA to ‘acquire’ Greenland.
Should I continue? This list is so easy to compile.