What’s the Ap-peel?

peeled apple isolatedPlease explain to me, why do so many apple pie recipes require one to peel the apples?  I can see removing the skin for cakes, cookies, anything requiring mashing or pureeing the apples. But for pies, crostatas, tarts, turnovers, and the like in which the apples are chopped or diced, what is the purpose of paring the apples?  I do not see where the skin changes the overall taste.  Please reply, sharing your thoughts.

In my kitchen right now are four apples and three pears (the apple’s cousin).  I plan on making a pie in the next couple of days, and guess what?  I’m leaving the skin on the fruit.

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