The reason, why we should usually check to the preflop raiser, is because, they will often have a range advantage. If for instance we defend with KT and see a KJ3 flop, the preflop raiser will have AA, KK, JJ, AK, KQ and KJ in their range, and if we lead into that, we might end up getting raised and lose a very big pot.
Moreover if we lead here with top pair, that means, that when we check, we never have anything better than second pair or a draw, and that allow the opponent to profitably turn almost any hand into a
bluff. So we need to check even some strong
hands to protect our checking range.
Admittedly its up for debate, how much we will get exploited in micro stakes games, because many opponents dont pay attention to, what we do, or understand how to exploit us. The player pool is also very large, so maybe we will never see them again. But this is the theory behind checking to the preflop raiser, which its nice to at least understand.
There are some situations though, where we are "allowed" to have a leading range. That is mainly the situation, when the opponent made a small raise from early position, and we defended our big blind and see a flop with only low cards like 663 or 875, because on these boards we can have more nutted hands than them.
