It seems to be a reaction to the restrictive design philosophy of Gnome but not moving too far from it at the moment.

For me, that’s indeed the main reason. I actually prefer their look and feel of Gnome, but absolutely loathe quite a few of their stubborn decisions, so I currently stick with KDE (which is also great). From what I’ve seen and tried, Cosmic seems to try and become a mix between those two.

That, and it’s neat having a DE that offers both tiling and floating and treats them as equally important.