Someone else, Teaandsympathy mentioned taxes, not me, so not sure why you think I have a weird hangup about them. I said "tracking my bank accounts" - they literally threaten banks if they don't hand over details of people who might be US citizens (which may be illegal under GDPR, but the UK government keeps rolling over for the US) which has resulted in "US persons" not living in the US being denied financial products - like insurance, pensions. They do that even if you don't pay US tax, even if you're not even in the US tax system or don't earn anything. And no, renunciation isn't as simple as that website may make it appear and it's been well documented and discussed how they continue to track even after people renounce. They even do it to those immigrants they love who get green cards and then move on from the US - they're "US persons" too for taxes, not much else.
I said Europeans until I started to discuss Ellis and Angel Island - those were over a hundred years after the US was a nation, so not sure where you're getting me calling colonizers Americans, but yes many American colonizers viewed themselves as American well before they became a nation and no, I don't really blame 'greedy nations' for all of it because I don't think people are their government. Things backed by the state, yes those are done by the government, but the vast majority of what I'm talking about had nothing to do with the governments of the people involved. Part of the American War of Independence was Britain said 'yeah don't be beyond that bit' and those US patriots said 'fuck you, I do what I want' and entirely ignoring the laws of all the governments involved. That's still not immigration, but it's what the country was built on. The country was built on force - if that's what you think immigration is, you must not think well of us immigrants.
And it's really weird to put Mexicans in with all those European groups. Prior to colonizations, Mexico was entirely American Indigenous nations, obviously - in fact the Aztecs were a major colonizer, happy to talk about how they and many others fucked up too. There were trade routes and conflicts across what is now "the border", but they weren't really immigrants at the time discussed.
Do people really think deaths of American Indigenous people ended with the pilgrims? Seriously? Is this like when people say British colonization was a 'long time ago', ignoring that it existed in living memory and is continued through corporations? The pilgrims weren't who was at war for hundreds of years with different American Indigenous nations. Every president during my lifetime has broken treaties and the laws of the nations involved, some of which have resulted in deaths. They're still "immigrating" in to 'manage resources'. The Constitution says treaties are the law of the land, and yet, those laws keep being broken. The laws that refugees can make their claim at the border, broken. The US government seems to break whatever laws it feels like, it'll be nice when they're dropped down a few pegs and have to play by all the rules they want the rest of us to play by.
And yeah, people have strong opinions about the US because they're currently the biggest power and I tend to have the strongest opinion for groups I'm part of. Discussing that the US was not built on immigration doesn't mean I think all US citizens are evil (again, people are not their government), but that the myths about how the US was built makes no sense if you consider how the US was built and are damaging to the US's ability to accept reality and move forward together (and it kinda erases American Indigenous peoples and their role in building things - read early European writing on the forests, they were managed that way much like British forests were managed, but better because climate and more biodiversity and a focus on food technology over industrial).
I mean, if you think US was built on 'legal immigration', what do think people who are legally immigrating to the UK now - people like me - want to do? What do you think those going to the US want to do with it? Cause I can see why people would be scared if they thought legal immigration was the same as colonization - but it's not, they're different, and it's okay to recognize that and recognize the US and many other nations were built on force. It doesn't make Americans or anyone else bad, it just means they should recognize their roots are not the warming tales people tell their children and adults should work together to build better rather than a wall.