This is still illogical. You can hire the original maintainer and pay an incremental cost, or you can hire a random developer and pay the initial learning cost + higher incremental cost.
If every company using a library chose the former, then every hour of development would be paid for (from the perspective of the maintainer) and the cost would be spread out across all its users.
You can use what is as is. Then you can ignore all of the other issues if they don't impact your bottom line.
Don't get me wrong, I like your corporate OSS financing model. But there seems to be not enough incentive for companies to use it. Why take ownership for a small cost, when you can use an imperfect thing with no cost?
If every company using a library chose the former, then every hour of development would be paid for (from the perspective of the maintainer) and the cost would be spread out across all its users.