And for the record, I read the comment about just sending a friend request as a work around to inviting, and how players that would not be willing to send a friend request would also not be willing to accept an invite. I feel that this is false. Many players see a friend request as a larger commitment than an invite. While an invite may just last for a round or two, accepting their friend request leaves them as a friend indefinitely unless you go in and manually unfriend them.
I personally only want to friend players that I've previously invited and know work/fight well.