I don't see the be-all-and-end-all of membership being about avoiding the possibility of missing games. Its more a matter of convenience in that I have a longer timeframe to complete my purchase.
Its more akin to paying a bit extra for a flight to get priority boarding or a pre-allocated seat. I won't miss the flight without it, but it means I avoid the scramble for overhead locker space with the riff raff who didn't pay the extra (for example).