Developers use these simulators to test how legacy 16-bit and 32-bit applications behave on the NT kernel. This is crucial for maintaining older industrial or enterprise software that may still be in use in specialized environments.
If you want a "hot" setup that actually saves your files and connects to the (modern) internet, virtualization is the way to go.
Communities Driving the Resurgence
: Advanced users have successfully run NT 4.0 for non-x86 architectures like MIPS using Key Features of the NT 4.0 Experience Advanced Windows NT | PDF | Thread (Computing) - Scribd
would entail if developed today, focusing on the "hot" or trendy retro-tech aesthetic. The Concept: NT 4.0 "Retro-Workstation" Simulator
Do not trust random ".EXE" files promising an NT simulator. Stick to web-based emulation.