Well for the UK they are because the UK is totally different to every other single country in the world. There is no other nation that doesn't have it's own national team but instead have teams for it's component parts. If it was a case that having a UK passport meant you could play for England (or for that matter say N. Ireland) why are we restricted to only playing people who have a birth right to play for the individual nation?The rules for eligibility cannot be different for any country under FIFA regulations, if its right for Croatia, its right for France and everyone else.
This came up in the Ryan Giggs thread, about how he never played in a major tournament finals. Even if he never played for Wales he was never ever elligible to play for England.
Other nations can get away with it as you say because, if you have a nations passport you can play for that nations team, but there's no such thing as an English passport. Everything I've seen about player elligibility for the home nations refers to either being born there, or parents/grandparents being born there.
Jokester

, thank god they wernt world cup qualifiers he bummed up

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