Cannot fully use Apple Shake application in macOS 10.13 High Sierra
Your question answers itself.


  Apple Shake was built on 32-bit Carbon API. I surely understand it's not 64-bit Cocoa API


Leaving aside the 32 bit versus 64 bit argument; Cocoa is entirely different than Carbon.  It's not going to run because the APIs that Shake is referring to (Carbon) are not compatible with what you are running now (Cocoa).

It's important to note that Carbon was deprecated in 2012 with the release of Mountain Lion (OS X 10.8.x).  Remember, why and when Apple adds/removes features is entirely their prerogative.


  In 2012, with the release of OS X 10.8 Mountain Lion, most Carbon APIs were considered deprecated. The APIs are still accessible to developers and all Carbon applications will run, but the APIs will no longer be updated.


As for Shake running in Terminal, this is an entirely different scenario - Cocoa and Carbon do not come into play - it's strictly a text based interface.

UPDATE:  After a bit of research, I discovered two things:


Shake has been relegated to "incompatible software" and Finder will not launch it.  Period.
There's a workaround (see below) to get it functional in El Capitan because the Carbon libraries are still included, though deprecated.  Note:  This has not been tested/confirmed in Sierra/High Sierra.  As this is deemed "Incompatible Software" by Apple, there's no guarantee that the workaround will fully work or for how long.  YMMV.


Work Around


Right-click Shake.App 
Go to Show Package Contents. 
Go to Contents --> MacOS --> shake (select shake not tshake);
Double-click shake. It should first open a Terminal Window and then Shake should be running.
Create an alias (a shortcut) of the file and place it whenever you want. Launchpad will not be able to see it, though you can have the shortcut/alias in your Applications folder.