Such tools have been around for a long time in the Windows world. The reason is division of labour. One of the dirty secrets about malware that lots of people hate to hear is that vast quantities of it get in through people pirating software and movies (which demand special "codecs"). After all why bother finding zero day exploits when you can just bind your malware to a Photoshop crack and watch hundreds of thousands of people come to you?
The opportunity is so vast that the black market divided into different job categories. There were the spammers who would buy bots from bot bot herders. The herders would buy "installs" of their bots from installers. The installers would buy binders from binder developers, obtain cracked versions of popular programs, use the binders to join the bots with the apps and then upload them to torrent sites. The installers weren't programmers so binders needed point and click GUIs, but that's OK, the value add they provided was knowing how to get around the blocks the torrent sites tried (uselessly) to put in place to stop this, along with simple brute force of numbers.
Often binders would also be combined with tools called crypters, which do what you'd expect, they just polymorphically encrypt the newly bound crack+app. Crypter developers competed based on how "FUD" their product was (fully undetectable). When AV companies learned to spot their decryption stubs, they'd modify it a bit and release a new version.
I watched this market for a little while a few years ago which is how I know all this lingo. It appeared to be a large and thriving industry. All driven by the greed of pirates.