Even though most people have convex utility WRT money this is not true for everyone. Some people need large amounts of money for big ambitious projects, others

Even though most people have convex utility WRT money this is not true for everyone. Some people need large amounts of money for big ambitious projects, others might have linear utility WRT money. For example, say you were donating a significant fraction of your wealth to effective charities. It is not clear you should have diminishing marginal utility towards these donations the way you would with personal consumption.