> You used to be able to report people for abusing that policy by saying "I don't know this person" after you declined the invite. However, LinkedIn are phasing that functionality out

Because Microsoft realizes that the only people who actively use LinkedIn are recruiters and foreign outsourcing salespeople (posing as hot girls) trying to weasel into the networks of people they don't know. Monetizing what used to be unacceptable behavior on the network is the only way for them to make it profitable.