More seriously how it s twisted ?

Well, someone descended from migrants hating later migrants is pretty twisted and a bit self-loathing, don't you think? There's got to be something wrong to want to change the rules so you wouldn't have existed if those rules had been in place years earlier.

Also how britain is an immigrant nation ? It s a 2000 year old country. Immigration wasnt even possible in scale 100 year ago because transportation wasnt good enough.

The country of Great Britain is only just over 300 years old, but let's pretend you meant England, which is just under 1100 years old. Boats have existed for a long time, but you're right that they weren't readily available to everyone, so early mass immigration events were often linked to invasions, such as the famous Normans or less famous Dutch (most recently in 1688), or expulsions and exoduses from nearby countries, such as France (Huguenots, who were about 5% of London's population around 1700 = 30,000, with about as many in Kent) or Flanders (the Strangers). Before England was unified, there were Angles an Vikings from across the North Sea, Saxons and Romans from mainland Europe, Celts from Central Europe before them, and farmers from Spain and Turkey before that. Before that, it gets pretty hazy, but pretty much all "Brits" are descended from a mix of these immigrants.