That explanation didn't make any sense at all. What do you mean group together? In a mining pool? That already exists with bitcoin.
Also, how is predictable behavior a bad thing? Perhaps the US mint should have super-mint months where they print 20 times as much currency as they usually do.
Random rewards prevents easily predictable behavior and forces people to group together to mine because a miner could work all day and produce one block worth 10 coins, or collaborate with 10 other people and produce 10 coins, some of which are worth a 100k coins, to average out the 10 coins.
It's more social engineering than technical engineering but still.