This is a very fair question.
For me, the reason for a hackintosh is just that I am tired of all the cables and having to swap between the two setups (like having one monitor for working, and one for gaming) while utilizing the performance when working.
I also want to utilize my iCloud Drive symlinking hacks to sync files / dotfiles between systems.
My gaming rig is currently running i4790k with a fairly decent motherboard (Asus Maximus VII) that I bought used for $200 a two years ago. It still performs like butter as long as you have a decent gpu connected to it. I seriously recommend this setup if you want to save some dough (or maybe the new Ryzen CPUs are better now tbh).
A sidenote regarding monitors: These are some exciting times to be working from home combined with having an interest for gaming due to the new monitors coming out, working for both.
I am currently thinking about the LG 38WN95C-W. Really expensive, but if you use it 8 hours a day for 5 years, I think I calculated it to be like 50 cent a day. :)
edit: Oh, and yes, as someone below mentioned, I love macOS and a lot of the things I work on require me to work on it.