The fact is, the community edition and the commercial editions have disjointed user bases. The community edition is used by a group of people who have the time and skills to deploy by themselves and who have no need of the many differences of the commercial versions. The commercial versions are feature-rich and effectively lock their users into a traditional commercial ISV relationship with the vendor. If these two were kept distinct, there would probably be no pragmatic issue. (Naturally, free-software advocates would still protest the existence of closed code, but that's not a part of this particular argument.)
But a vendor that mixes these two encourages exactly the market confusion that OSI was designed to minimize. If they claim to be an open source business and use the presence of the community edition as a credential to sell the proprietary versions, they wrap themselves in the open source flag and their actions are exactly the gaming of the maturity of open source that I believe should be challenged.
Will Nginx try to wrap itself in the reputation of its previous good open source citizenry while encouraging its customers to do without the flexibility of open source? Time will tell, but I strongly encourage the company to avoid this trap.
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