With brexit people had only one opportunity to vote, so it was possible to mislead a large number of them, about unknown things happening in the future. With a system like this they could change their mind as the situation changes, so agitation would not have the same effect.
As the saying goes "You can fool all the people some of the time and some of the people all the time, but you cannot fool all the people all the time", so this would in fact be a safeguard against things like Brexit.
