I can't figure why some programmers feel that working on a 13 year old compiler is a good idea. But that's one of the great things about software development - folks can do whatever works for them
(Only to add) A large portion of code, libraries in industries (industrial robots, medical applications, IC related etc) are still using VC6 as a must. These companies are not usually not IT oriented, which may be why they don't care about upgrade, it costs a lot and upgrading old libraries source code is always a nightmare, even to those in IT mainstream.