There are lots of very good photos/art/pictures with huge amounts of people in them, like "Night Watch" by Rembrandt, which I happen to like. However, there tends to be a *focus* to the picture. A place your eye goes, first. And a feeling that you know what it's about. And the focus is somehow separated from the rest of the picture. Maybe the focus is shown by distance (near to compare with far?), or color (bright spot amongst the drab?), the amount of light on it, or everyone in the picture is looking towards one thing, or even a circle/triangle/square of things/people that are the focus.
This is not easy to learn, and harder to make happen. (I have so many photos that are just, well, messy, and not focused, and they're not making it into the world. And I've done art that didn't work, as well.)
As for getting brave enough to say something, you did say you had a skin like a rhinoceros (or something equally thick) and I decided to test it.
Some people don't take criticism well at all, even when tempered by a list of what's right. You have taken the criticism well, which is good.