I confess I haven't written any.
On the other hand, MS has written SIX PC OS's (95, NT4, 98, ME, 2000, XP) in the last seven years.
Eight if you count 98SE and the two flavors of XP.
I guess that makes them better.
Or something.
However, "better" and "bug-free" are two different aspects of a product.
I guess, I have to say it straighforwardly: when one formulates expectations (such as seeing the bug-free software) one needs to know what is involved in the creation of the product.
We've built a lot of highways, and still have accidents on them. Think about that analogy.