There was a brief time when aptitude was smarter than apt-get (it was smart enough to remove auto-installed dependencies when you removed a package, for example). During that time, the advice was to use aptitude instead of apt-get.
Those smarts were later moved to apt itself, but it's still a part of the folklore.
I can see the search being useful though.
Seeing as my muscle memory is set at apt-get, i'll stick with it for the moment.