How is it bad for people to find dates in the office? Plenty of people meet their significant others at work. It's a bit bizarre to treat courtship as "bad".
I think it was more along the lines of "shotgunning messages to any women in the area who will accept your connection." If you were hitting on all the women in your office I'd expect HR to want a chat.
It's not bad to find dates in the office. It's bad to message people on LinkedIn with the specific intention of meeting with them for non-professional reasons. There are other, non-professional networks for that.
