While I can't help you with your opinions and beliefs I do understand what you're saying. MongoDB may have done this purely to for marketing. They may also genuinely believe the change still leaves their code being free software. I don't know anyone there.

The change, if there is one, won't be because of you or me. It will happen over a few years time or it won't happen. It will be driven by what people accept and what they don't. A few extremely loud voices may turn the tide in either direction so maybe there's good reason for each side digging in their heels and making noises. Either way, each individual's idea of free software will exist under the names that evolve out of this skirmish. Both businesses and coders will adapt.