The idea of fixing bugs before implementing new features is that the bugs in your program might interfere with new features. Or finally fixing that bug requires you to do some large scale refactoring, a completely different approach, who knows.

So if you happily go ahead with new features, you might find out later that you're building on sand, and fixing the old code plus all the new code might be massively more expensive.

Regarding version control: I think this depends on your community. In 2000, it was standard knowledge in University/UNIX/Java land that developing software without version control is not only a bad practice, but just unprofessional. This might have been different in all those small shops doing VB or Flash stuff.