Before the cross-server LFG system I tended to know a lot of people on my server because I grouped with people on my server. When the cross-server LFG tool hit I got surrounded by strangers with whom I was never able to meet again even if I wanted to since there wasn't a way to /friend them even if they were nice.
I completely agree. To expand upon this, not having it cross realm created the sense of a server community. Each server had something different and unique. People that grouped up, if someone did ninja an item, it eventually got around and had its consequences, in that people would know who the good and nice players were, and knew who not to group up with.
EDIT: This is not the original posting, that is the next thread below. This thread was placed as the first posting due to a time stamp bug in the forums at the time of replying to a posting.