Thank you guys, you almost convinced me. ;)
But consider the following:
1. IMHO GNUstep and NEXTSPACE are not the rivals of MacOS (or any other Apple product) in any form. Moreover GNUstep along with NeXTSTEP can be a good starting point to future developers of Apple ecosystem (Obj-C and Swift development environment without need to by a Mac from the start). I see it this way.
2. Apple never used graphics from NeXTSTEP in their products. None of them.
3. There's no icons for all applications (see Preferences as example) in GNUstep or GNUstep themes. So I need to find another set of icons in GNOME/KDE themes for example. But it will definitely kill NeXT style of NEXTSPACE.
4. NeXTSTEP/OPENSTEP is dead for 17 years (latest patch for OPENSTEP dated 2000). It can't be used on modern hardware with modern software. That people (like me) need NeXTSTEP equipped with all new functionality that OpenSource have got during these 17 years.
Anyway, I definitely understand the problem. I'll do all my best to find a solution.