Im pretty sure it disables report if you report people that noone else reports too often. So a good practice is to always queue with at least 2 friends and triple report. This gets around the problem of getting your report function taken away and also guarantees a ban on the reported player.
We have yet to see if this game caters to snowflakes and goes the 'concord route' of fails or if this is just regular valve being bad at setting up report systems.
