I see you watched question time too
I think its the job of the politicians to give people the information about what the treaty actually means, the important aspects of it. Then people can vote with an understanding.
I don't think it corrupts the vote if some people want to be out of the EU. I'm sure they'll happily settle for not further integrating, given a choice between further integration and not further integrating. They're achieving the 'lesser of two evils' from their perspective, and I think its right that they should have a say too.
If the parties never intended to give people a vote because it is too complex and they don't feel they could get people to understand what it meant, then they shouldn't have promised they'd do it really. Breaking the promise just puts more people off politics and makes them believe the politicians are even more corrupt than they already think they are.