Do good bridge players memorize all cards played?
Obviously, this answer depends on your meaning of the word 'good'.  However, I consider myself a good bridge player, and find myself not often needing to track the nuanced difference between 6 and 7.  Most hands are not decided in table play, but in the bidding, and most are determined by leading, the high cards and the trump suit.   There are situations where I would need to track a spade 6 or 7, but often that's when I've got a hole that I need my partner to fill, or attempt a finesse.  In such situations, I'm looking specifically for those problem cards, so I don't need to track every card.  

There are unforeseen situations where tracking every card could give a slight edge, but those happen so infrequently that it won't make much of a difference in one's overall 'goodness'.

Incidentally, there are mnemonic tricks that allow one to easily track all cards, I just find it not worth the effort in standard bridge.