Harassing random strangers with (supposedly respectfully worded) unwanted intrusions because
1) you make unwarranted assumptions about their character on very little information,
2) you want them in your group based solely on those (often inaccurate) assumptions, and
3) meanwhile you must also think they're too stupid to be able to hit your LFM if they had been the least bit interested in joining your group for whatever raid/quest you're running.
Right, got it, the "good" old days. Good riddance.