You can make thin mints at home, just not a lot of people do it because they don't feel like looking up a recipe for them. I care that's who! there are chocolate chip cookies that come in a box so don't discriminate thin mints just because they come in a box.
Just because they aren't simple doesn't mean they aren't fun to make. The most likely take longer to make so you get more bonding time if you are making them with someone else. Have you even tried to make homemade thin mints? All you need are three things: peppermint extract, 10 oz. semi sweet chocolate and Oreo's.
However, for little kids time is everything. If you are making cookies with little kids, you want a short and sweet cookie to make, because kids like simplicity. something they can do. Once you get past that, they may become frustrated and bonding time turns into rampage time.
Not all kids do that. Some are very content just spending any amount of time with their mom or dad or whoever. And it's not like they have to sit and wait for them to come out, they can go off and play while the parent makes sure they don't burn. It's not like they can take the cookies out of the oven anyway.
Kids like to help. Yes, they can help make thin mints, but how much would they actually get to do. Making chocolate chip cookies allow them to help from start to oven. Plus, they are the best to eat when they come out of the oven.
(and cooled a bit) They get to help measure and add stuff and stir stir the batter. Simplicity is sometimes best.
With chocolate chip cookies, you get the mix pre-made. While with thin mints the only thing you don't have to make is the cookie part. The rest of the cookie, mint flavored chocolate, you have to make. Thus a child can do more when it comes to actually making the cookie. Chocolate chip cookies they get to shape them that's about it.