It's not quite the same as a cracked copy of Windows, although from a certain viewpoint it's in a similar vein...
The only reason to run a cracked Windows is if you don't have a legitimate copy. Strictly speaking, that isn't the case for Hackintosh; you can have a licensed copy of OSX, and since OSX doesn't use cd keys, there's no need to crack it in the usual sense.
However, OSX is built to run on Apple's hardware, and running it on non-Apple hardware is against its EULA. How much sleep you lose over violating the EULA, especially if you own a legit copy of OSX, is entirely up to you of course. To my knowledge Apple hasn't actively done anything to fight the Hackintosh "movement."
Furthermore, some changes to the OS have to be made by injecting files into the installation media in order to get it to install on non-Apple hardware. Supposedly OSX runs pretty well on Intel-based Hackintoshes, but AMDs have more trouble, and despite a fair effort I was unable to turn my PC into a Hackintosh.
The real concern with Hackintosh comes with the fact that making required changes to the data on the installation disc is above the experience scale of most users. I've been using PCs for 20 years and I found the stuff relatively confusing. That is why most people who fiddle with Hackintosh installations download their pre-patched installation media from torrents. So even if they own a copy of OSX that's not likely to be the copy they try to install. If you're downloading an OS from a torrent, there is almost no way of being sure something malicious has not been added to it - trojans, worms, viruses, keyloggers, whatever.
Personally, I try to respect a software EULA to a degree to which it seems reasonable, but if I have a legitimate retail copy of an operating system, I will install it on whatever architecture I damn well please. I think the Hackintosh stuff is fun to explore, and OSX is a great operating system, but it's not exactly something I would recommend, or even assist with.