It is more respectable to have a non-altruistic hobby than to have a non-altruistic job. If I say to a public servant that their career doesn’t make the world a better place, I’m being offensive. If I say to a chess player that their hobby doesn’t make the world a better place, they will likely agree. It’s no accusation.
People also like to have jobs that make the world a better place, whereas they don’t usually care about whether their hobbies do. A few people volunteer or create things for the enjoyment of others of course, but it’s not much of a negative if a hobby doesn’t achieve altruistic goals. People rarely worry ‘I must get out of this hockey; it’s so draining to think all my efforts aren’t helping anyone, and when I die there will be nothing to show for it’.
At first this may seem unsurprising. Jobs are where you exchange socially beneficial work for money, while hobbies are where you enjoy yourself. But why must they be grouped that way? By definition jobs are where you get money, and pleasing others will tend to get you money, but if you are already making money without seemingly making the world a better place, why try so hard to add your dose of altruism there? It should often be easier to change to a more altruistic hobby than a more altruistic job, since you don’t need to find someone to pay you for it. And if you take up an altruistic hobby, you don’t displace anyone.
Here’s a hypothesis for why altruism matters more in jobs than hobbies. Humans are sensitive about receiving money, and about others receiving it. We intuitively feel that material wealth should be divided fairly amongst the tribe and are suspicious of people who accumulate it without sharing. We allow inequality if it’s deserved in return for other socially beneficial actions, but we monitor this closely. We can’t believe the rich really deserve it, nor the welfare dependent, and this suspicion of cheating colors all our dealings with them. When we are given money then, we must feel and look like we deserved it or we risk deep shame. So the very fact that employment gives you money means you need a clear, tellable justification about altruism.
On the other hand we don’t crave justice in enjoyment of leisure time. The fact that someone is having a really interesting conversation with a friend without apparently deserving it doesn’t make the rest of us feel cheated and suspicious. Why don’t our fairness instincts kick in with leisure? I expect because leisure has always been too hard to count and measure and not directly useful enough to survival to redistribute, unlike concrete goods. So you don’t need any altruistic justification for having fun. Notice that if people wanted altruistic jobs mostly due to direct desire for altruism we would see a different pattern; they would be similarly interested in altruism in other pursuits.