A large number of people don't turn down free things...I'm assuming you mean with 'paid for' that someone else has paid for it?
But pay for it yourself, then people measure up the cost/benefit ratio, that's just normal.
What I mean is - over half of those 187 countries have never been in a position to obtain or develop nuclear weapons regardless of whether they feel the need for them or not - something Corbyn should be well aware of - his claim is blatant misrepresentation - from someone else I'd let it slide but hes the one talking up a new era of honest straight talking politics, etc.