But the Finder doesn't just "Find" (Score 2, Interesting)

Sure, you can let files accumulate on your hard drive with all the organization of a pile of sawdust, but finding the files by Spotlight or a Smart Folder query is only the beginning. You will want to copy or move one or more of those files, so it is vital to have an application with a good interface to arrange the move between target and destination (e.g., hard drive -> optical). Spotlight/Smart Folders are by no means ready for that, and by the time you add that functionality, you're back to something like the Finder all over again.