Well, why shouldn't it? The way I see it, a FOSS technology stack should be the default, and using the proprietary and expensive one must be justified, as in saving significant amounts of money, or coming with some absolutely necessary technical advantages. The fact that SO is an exception (a high-profile site built on MS stack while not being affiliated with MS) kind of proves the point.
>a FOSS technology stack should be the default, and using the proprietary and expensive one must be justified
You're ignoring overall Total Cost of Ownership (TCO). Licenses are a drop in the ocean compared to the cost of long term ongoing management of your platform(s).
