You don't need it -- don't use it. Don't ruin it for those who do need it.
Also, how the fuck is getting a group with SAME RANDOMS by manual grouping is ANY different from a party from LFG tool?
So, you don't have 5 minutes to look for a group manually but you will have 1-2hours to finish a dungeon ? Please don't promote laziness (nicely wrapped as convenience) , it only creates problems in the long run - community wise.
The current system could be improved with a better LFG interface like some of the previous posters said, but I would hate to see it go the WoW road with an automatic party system.
Manual grouping promotes responsibility, and actually provides a feeling of teaming up (at least for me). Because it's harder to gather a group by manually doing so, it also rises the odds that the party will not disband earlier, they will try their best to help each other in order to finish the dungeon. It creates a certain level of reputation among other players as well.
Automatic grouping is an impersonal system, where you care only about yourself because in the end if you don't like your group you can just leave and press the magic button to join another group. Haven't you noticed that most of the stories about LFG in other games are starting with "So I was in this dungeon with some 4 *idiots*...". How come the the OP is never the *idiot* ? The problem with an automatic LFG is that people will not try their best to make things work (aka working as a team). You can't expect much from the others if you, yourself, are not prepared to offer anything in return (patience, advices, help... etc).