And unfortunately when people are left to speculate, many assume the negative, in part because we project our own proclivities on others.
I wonder if the multiple independent developers included Blender, GIMP, Inkspace, Kdenlive, and others insofar as they have been part of the tooling and construction of the Zorin interface, chrome, etc That would be a good thing. And although technically there is no obligation to do so, it would do no harm for Zorin to credit them. It would be an ethical positive.
Also, when it comes to the "Zorin OS Pro" edition, (an unfortunate label in retrospect), bundling the many extra programs isn't an attempt to co-opt free software and try to make money off of them. It is the convenience of not having to find them, to choose the type (apt, flatpack) and repository for download, and to make sure they are configured properly for Zorin. As for other extra features, the four desktop extensions are nice. More valuable I think is extra individual support offered. But all extra features are fundamentally "thank you" gifts for the $50, solicited as a way of supporting the entire Zorin project. (Hmmm.. the "Thank You" edition?)
Correcting misperceptions is difficult, because there are automatic associations with the word "Pro" born of long experience in the way that word has been used with other programs, etc. And what I really cringe at, is that many stay away because they don't want to, or can't pay $50 for the "complete" pro version and just getting Zorin Core (the word "core" having associations with "stripped down") wouldn't be satisfying.