With 30% of the population being obese today, with the average male height increasing from around 165 cm to nearer 180 cm, you'd think that seats and interior dimensions would have increased over the years to cope with the general population.
So, you think that it's fair for 70% of the population to have to pay more to subsidise the 30% who are obese? Larger seats means less seats, so everyone will have to pay more.