If he plays tf2, his opinion is just as valid; maybe more valid, than everybody else's. He represents a demographic of tf2 players, one which is probably far larger than the group of mappers debating in this thread. You need to remember that a good map should appeal to as many tf2 players as possible, and you must achieve that by any means necessary. Just because he isn't an expert, and maybe hasn't played a lot of tf2, doesn't invalidate his opinion. Instead, learn from it and teach players like him in your maps. If he missed your finale, try adding a pre-finale effect, and vectors to draw attention to it. If he got lost, clarify your layout with arrows and well-placed windows. And if he failed to notice you game-changing flank route, then the pub players will too. There is not greater folly than to criticise your critics. That's my 2 cents.