Think about what you are asking for just a minute. If blocking blocked playing against people then people would just block anyone better than them that they faced.
I get its frustrating playing against cheats but short of actually having a better instant reporting system in game that maybe suspends matchmaking against them temporarily while your report is assessed there is not alot you can do to improve it.
Blocking exists purely for messaging purposes. It would be silly to have it block other players from appearing as a match. Though think it will stop them appearing as a teammate in Rush.
