I wonder if a lot of your opinion stems from the kind of coding that you do merlyn. Seems to me that you're lucky enough to be able to work on your own code most of the time. And would it fair to say that most of the programs that you write are small demos of particular Perl features for training courses or articles?
Nope, this is 22 years of professional experience talking. While it's true that a good portion of my programming activity for the past two years has been original solo work and small-to-medium programs, I speak also of the times when I was writing very large programs and systems (tens of thousands of lines of code) and working with other team members. Never used a debugger then either.
And if the code the client throws at you needs a debugger to trace it through, I'd argue it's not maintainable, and should die the death it deserves. I can't tell you how many pieces of code (or entire programs) I've just simply thrown away and rewritten.
As an example, did you ever step through the printf in the C library? No? Why? Because it's well-written, and you can understand it from the specification. If the code your client throws at you doesn't work like that, then kill it. You can't patch a Yugo into a Porsche. Ever.
To do any less is to sell out for dollars. Unethical, in my book.
If you need to debug code, it's wrong. Start over. Redesign. Recode. Rethink.
-- Randal L. Schwartz, Perl hacker