It is incredible easy to build a nice one screen application with not very a very complicated background logic. Normal people like a nice graphical interface with a few buttons, and with Classic VB you can create them very easily and iterate and customize the form.
My last big problem was that it doesn't have a build in sort function, so you can use a n^2 sort or write a good sorting function by hand :( . When the logic start to be not so easy, there begin to apear problems.