The reason is due to the symbolism, and it is all positive. The movie kind of mirrors Donald Trump's life as he was likely recruited for the Presidency by the military. I'll just stick to the main plot lines of the movie.

The movie starts with a Christmas Pageant that involves Kevin and his older brother Buzz. During Kevin's solo, Buzz takes his (fake) candle and that of another kid's and puts them both under Kevin's ears. This results in Kevin punching Buzz and knocks down the entire choir in the process. He is blamed for this and will not apologize to Buzz for his actions.

He gets separated from his family and ends up in New York. He ends up at the Plaza Hotel, which was owned by Donald Trump at the time. He is found due to using his Dad's credit card to book a room. While exploring the city, Kevin visits a toy store called Duncan's Toy Chest and learns that all Christmas Eve proceeds (current day) go to the local Children's Hospital. Naturally, Marv and Harry are in town and intend to rob that toy store since all the cash will be left in there until the 26th.

Ultimately, Kevin helps with Operation Ho Ho Ho which captures the crooks. Remember that Q said that "this is a movie" and that "The Military is the only way." It is certainly the case for Home Alone 2 As Kevin represents the military and conducts an operation to save the kids.