A lot of people's open source work is mainly limited by competition for time -- namely, their job, spending time with family, chores/housework, other hobbies, r

A lot of people's open source work is mainly limited by competition for time -- namely, their job, spending time with family, chores/housework, other hobbies, relaxing and sleeping. More money may help entice more time to be taken from some of those other things, but some of those are more or less fixed (job, chores), not sustainable to give up for long (sleep, relaxing) or simply not worth a small (or any) amount of money to give up (family). Enough money and stability that someone can give up their day job -- that's a different story. But that's a very big jump, and suddenly even $400k doesn't really go that far, assuming you can even get that money. There's a reason very few open source projects have a full-time developer being compensated by the community.