Because the EU did not think that the UK would be better off outside the EU. 87% (86 votes) Because the EU did not think it would be worse off without the UK. 13% (13 votes) Total votes: 99 Presentation videos: Embedded video for Why did the UK's threat of Brexit fail to gain sufficient concessions from the EU?Embedded video for Why did the UK's threat of Brexit fail to gain sufficient concessions from the EU?