Yes, I write fairly boring applications. But the point is that C is mostly cross-platform for those boring applications, whereas the the "cross-platformness" of CSS and SQL fall apart for even the simplest of tasks.
Again, I think you're viewing this through the lens of relative experience. I have seen tons of C code which required substantial fixes to work portably (bonus points when this was exploitable) and I have plenty of CSS and SQL which hasn't had to be touched in years.
