I think the reality is, if its a hobby project supported by one person then money doesn't really solve it. No company should put itself in the position of being reliant on some random individual on the internet whether they are willing to pay them or not.
Of course, adopting this stance takes away opportunity for many small time open source projects to become popular in the first place, and the general incentive and opportunity for open source to succeed.
Money solves this by paying the original person or someone else to do what they need and provide the level of service and guarantees that they need. The whole point of open source is that it doesn't have to be the original developer.
I'm glad you brought this up. It's really core to the value of open-source as an activity. It creates the possibility for a project to become much greater than what it would have been if it was limited to the person or organization that originated it.
Of course, adopting this stance takes away opportunity for many small time open source projects to become popular in the first place, and the general incentive and opportunity for open source to succeed.