Why are you using commercial software?

From Finding and Understanding Bugs in C Compilers:

There exist many more commercial C compilers than we could easily test. The ones we chose to study are fairly popular and were produced by what we believe are some of the strongest C compiler development teams. Csmith found wrong-code errors and crash errors in each of these tools within a few hours of testing.

Because we are not paying customers, and because our findings represent potential bad publicity, we did not receive a warm response from any commercial compiler vendor. Thus, for the most part, we simply tested these compilers until we found a few crash errors and a few wrong-code errors, reported them, and moved on.

Yet another example of the multitude of inherit contradictions in attempting to develop software commercially.