It's funny but it's true. There's tons of production code out there making MILLIONS OF DOLLARS for it's company, that 1. compiles with 10,000 warnings, 2. has no unit tests, 3. has global variables and gotos all over the place, and 4. exhibits buffer overruns, undefined behavior, and thread-un-safety. In the commercial SW world, you almost never get time to polish the stone. You race to your deadline, release, and then race on to the next mess.
When I was a young engineer I used to think, "One day, ONE DAY, the company will go down in flames for all this bad software practice, and then I can stand triumphantly among the ashes gloating over how I was SO RIGHT to worry about compiler warnings!"
It never happens.