I agree that the who system has potential. I think you hit key points that should/could be change to make looking for a group better. Updating the who system is much better then putting in an instant queue LFG system. I think the current system could use some upgrading but i would hate to see groups being put together randomly. The player should have control of the group making grouping much more social.
here an example of the Who system updated (like you said) vs. a lfg system that put groups together.
Example: while look for a group for a FP, you come across a trooper you played with before who is flagged in Who system for the same FP as you. If you had the lfg system that auto groups people together in place, you wouldn't have know he was lookin for the same FP as you