Malware programming is actually a very interesting topic to talk about as Malware have potential to make millions if not billions as ZeuS made millions for their owners. Apart from that it also allows the author to gain experience as programming Games is *easier* than Malware Programming as there are way more techniques you have to implement to make it a successful Malware such as:
1. Root kit - Need to learn Hooking , Injection , Driver Development , Assembly
2. Social Engineering - Understanding Human Physiology
3. Spam and related - Understanding Protocols
Look just to implement few of the basic features you need advanced level knowledge about programming. Malware programming challenges the authors with obstacles such as Bypassing AV using Injections & Bypassing Firewalls.
If you Google the "worlds best programmer". The results show hackers are the best so this shows Malware Programmers have more than average programming techniques.
I can also tell you that Malware[s] have great deal of historical significance which still are believed today such as "Hackers are all bad". Malware is also now run by Mafia's and Other Criminal Organizations.
There is a lot of money to be made there but the consequences are there too so, the desperate will jump into Malware field.
I am not going to tell you to program Malware but I respect those programmers as they work alone yet bypass the most sophisticated Anti-viruses which is usually programmed by few Hundred people. This shows their Skill Level is above most programmers.
A article showing the money made by Malwares: http://malwarelist.net/2012/12/06/new-zeus-botnet-eurograbber/