While this sounds very nice, in my opinion you are very fallacious. What you are actually doing is a bear's service. You are denying yourself a justly earned win and are denying your opponent the opportunity to learn. If your opponent makes a mistake punish it, take his queen and next time he will think twice about where to place it. Sometimes though if I see a mouse slip or an obvious miss-click I will be courteous enough to let it slide, but if my opponent makes a conscious mistake then it is his fault and he should learn from it. Either way don't expect most people to return the kindness, in chess or anything else for that matter.
Bad Manners
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Imagine for a moment, a player opens with a half-baked queen attack, where black defends until queen makes a mistake and black takes queen. I hate that attack and I always take the queen. Some players resign. I don't care.
But if the game involves an actual strategy and it's an even challenge, where black defense thwarts white's intricate attack and now the mid-game has finally become interesting, if white makes a mistake that jeopardizes the queen, I usually don't take her. Or if I move a piece that puts white's queen in jeopardy, I say, "En guarde", which is the polite way to play chess and let the opponent know their queen is about to become toast.. or maybe French toast...
So, the opponent either moves the queen out of danger or says in chat, "Oops! My mistake" and moves another piece instead. Then, the player has indicated that they made a mistake and they return my politeness by inviting me to take their queen. So, I usually do and know that the stage has been set where I'd better be very careful moving my queen. Both types of polite players usually become my friends and we play again on another day.
But if the player says nothing, moves the queen AND takes a major piece of mine, such as a rook, I feel cheated because I could have said nothing and taken their queen. Such miscreants are the like the savages who hoarded cleaning supplies and toilet paper at the beginning of the novel corona virus pandemic.