Personally, I don't see why the search function from FFXI isn't implemented. It works and is very simple to use.
In the mean time, I think they should just shut off the shout function for one day and force people to use the search system as it is now.
It works just fine, people just done use it. Granted, I've never been invited to a group, but I have made party myself using this feature.
All in all, they're more likely to work/fix/improve on something players use compared to something they don't.