I think this is one of those issues that only exists in theory, not in practice.
If a company reports a bug in a clear and helpful way, it's probably going to get looked at anyway.
Also, if a company cares enough about Wix to bother finding and documenting a bug, they should be willing to pay $60 for the software.
So this is only a problem in the case where a company finds a bug, decides to report it, refuses to pay a minimal fee, and the maintainers are strict enough with themselves to ignore it because of the source. That feels unlikely to me.
If a company reports a bug in a clear and helpful way, it's probably going to get looked at anyway.
Also, if a company cares enough about Wix to bother finding and documenting a bug, they should be willing to pay $60 for the software.
So this is only a problem in the case where a company finds a bug, decides to report it, refuses to pay a minimal fee, and the maintainers are strict enough with themselves to ignore it because of the source. That feels unlikely to me.