I will attempt to explain a view on this:
1) When the cross server LFG tool was implemented it in essence encouraged people to adopt all the wrong behaviors that made grouping fun. Dont like the instance. Leave. Feel like need rolling on everything? Go ahead, your chances of ever meeting up with these people again are miniscule. Even if you do, its not like they are on your server. Feel like raging against people, instead of even attempting to help them? By all means, enjoy it. Not like theres any real consequence for your actions.
In essence, it took every negative aspect of the internet, and turned it loose on the game. And thats what people consistantly complain about.... especially when using term like "wow kids".... when ironically perhaps, the people they speak of are quite probably adults. At least legally.
2) When I logged into today, I proceeded to swap over to republic side to play my gunslinger. I was hunting for a group for ess... it took all of five minutes, if that. Upon arrival, we plowed through the instance with relative ease.
Then the smuggler chest dropped. The Jedi rolled need on it. And won.
My thought was why? However, rather than pitch a fit, I just quitely finished the instance. I marked the name of the player that did it, and now I can completely avoid him. I couldnt do that with an LFG tool.
3) Part of the game is engaging each other to complete group quests and flashpoints. Part of the game is actually traveling to those flashpoints, or areas. Remove those, and your remove a portion of the game. Dont like them? Why are you playing the game? The game involves a certain amount of exploration.
4) Finally, the simple fact is that the negative aspects of the LFG tool are legion. The beneifts are small. I would rather hunt for a group or partner then be forced to deal with the degredation of peoples behavior when there is no consequence for their behavior.
Its that simple.