Although this statement is somewhere between meaningless and false, the primary issue is not with the presence of bugs in Mathematica but rather with the frequency of bugs as compared to that for programs of similar complexity. Frankly, the effort is better expended on correcting the issue than on arguing about it.
> To you, Mathematica is mysterious, because you fight it rather than > using it.
I have been using Mathematica for solving a practical problem for several months and am quite happy with it overall. However, it is already obvious from personal experience and numerous reports on this list that quality control at Wolfram Research is at best severely lacking.
> I've been using Mathematica to do practical work since version 1, and > I've never encountered a bug in its numerics.