I understand the objection but in general I support the Commons Clause-- as long as developers can easily opt out for projects where it isn't desired or doesn't make sense.
Open source developers are building software for free that is then used by extremely large corporations to make vast amounts of money without compensation to the original author. Even worse much of this revenue comes from business practices that the original authors may find highly objectionable including mass surveillance, "surveillance capitalism," and data-driven propaganda, con artistry, and manipulation.
If you create open source today you have no choice but to indirectly offer free labor toward the construction of a global surveillance state. The commons clause offers a way out while still encouraging people to use your software for personal, private, academic, and other purposes and retaining the openness of open source.
The "free as in beer" part of OSS is a relic of the 1990s when the prevailing enemy was "embrace-extend-extinguish" at the hands of (mostly) Microsoft. It was sort of a growth hack to enable open source software to gain critical mass and challenge closed source proprietary platforms.
Times have changed. Today the big threat is SAAS walled gardens, surveillance capitalism, and other business models that in many cases run on and depend upon open source. In some cases SAAS can verge on piracy-- not necessarily in the legal sense since nothing is being done to violate any license but in the moral sense of profiting handsomely from the work of others without compensating them.
Edit: I will provide a concrete example of the last point: RethinkDB.
RethinkDB was probably the best NoSQL database, at least before Mongo was improved enough to challenge it on robustness and versatility. It still has features Mongo and others lack.
Unfortunately RethinkDB the company failed because... well... nobody paid them. Instead they paid services like compose.io to run RethinkDb for them in the cloud. Cloud SAAS database services were making more money off RethinkDB than the database's own developers were. In the end they failed and the project is now almost abandoned.
There are numerous similar examples. AFIAK the Commons Clause would have prevented this, allowing either RethinkDB to capture their own SAAS market or charge compose.io something for making money off their software.