Because that is how voting works. People choose and the most popular choice wins. Only they already voted, and it was to leave.
Why are you afraid to let people vote now then? They now have had more time to ponder how real were the promises and what the consequences are.
You may try to deny what´s happening, but the problem with reality is that is there even if you don´t like it: All the economic indicators of UK are going downhill, including the leadership in finances, the industrial capability and the ability of updating salaries with inflation even at full employment. The interest rates are also now going to catch the families on the wrong foot.
And no, you cannot replace more 25% of your exports without a huge damage to the country, that´s not how markets work.
Oh nice debate tactic there, you really put me on the defensive. I sure am scared! DOOM AND GLOOM! THE SKY IS FALLING!
Really though, I explained multiple times already why this second vote is a fraud and the EU itself was a fraud to begin with. What you are talking about is not reality, it is a synthetic manufactured illusion created by the media. Another vote just gives these con artists another opportunity to rig it right this time. Any problems you can point at were ongoing previously or purposely exasperated by the EU in a punitive attempt at punishing the UK for voting to leave. They are desperate because all it will take is one more major contributing nation to leave before the EU is a non-entity.
Also everyone might want to take note, this was Hitler's ultimate goal, a unified Europe. Just saying...