It's not so much that somebody can make money with it. It's that you, the project maintainer, will be reaping all the monetary benefits for yourself. With open source software theoretically anyone can benefit. If you don't like what the maintainer is doing, you can fork it. In this case, though I believe the commons clause does allow you to fork it, you would still be the one reaping any monetary benefits from the fork.
In my opinion the biggest issue with the commons clause is it no longer makes logical sense to fork the project. If the project dies because you couldn't make any money off it, and you don't go back and relicense your work, the code is practically dead as an 'open source' project. Well, that and that the consulting clause seems to be just sitting there waiting for a major court case to decide what it truly means (even the lawyer who led drafting the clause admitted as such [1]).
[1] https://github.com/fossas/commons-clause/issues/4#issuecomme...