That's a terrible analogy.
The crux of Spotlight is its ability to search within files. The crux of Safari is its ability to render web sites.
Searching within files is to Spotlight is NOT as Safari is to playing Flash content.
It's a perfect analogy that pokes an immediate hole in your argument, thus to you its terrible. It searches, maybe it doesn't search everything you want it to, but it does search. Again, Apple is likely working on adding the functionality of content searching however its not complete yet, thus apple indicates on their site those features aren't there.