The days when manufacturers specified a fairly low pressure with the option of raising this for load or high speed is mostly going or gone . Manufacturers use higher pressures when testing to get the best possible fuel consumption and emissions results for official figures used by governments to set taxation and environmental classes etc.
So thats the pressure they must specify as standard . They can probably recommend settings higher than this as emissions will be better. But probably not lower although IIRC a while back I saw one car (I cant recall which) that did have the high pressure as standard, but mentioned a lower pressure that gives better ride comfort.
they may also have to sell the car with the type of tyre used for the tests. I think there is a car that just manages to avoid the london environmental zone charge on one of its tyre options but not the other.
Could be the reason that Honda cant approve the much more common 195/55R16 tyres for the crosstar ,even though they are a close equivalent.
Its quite likely the Jazz suspension is set up to perform best at this high pressure . Any reduction would increase fuel consumption and may be detrimental to the tyres and handling etc. Honda may see no need for a higher pressure option as its already quite high.