Very few people (apart from those who unfortunately die young) pay in anything close to what they get back- both in terms of state pensions and private pensions, especially public sector schemes.
And of course the vast majority of income tax is actually paid by the top few earners (apart from those who evade it).
The joke could go on to add all those with disabilities, pensioners who live beyond 80, all those who get tax credits, pension credit and child benefit and most children.
But the joke still made me smile I must admit