Every Major League ballpark should be open to the public during the offseason

At the end of September -- well, October if you're lucky -- we say farewell to our favorite team's ballpark, resigned to the fact that we won't get those spectacular views or that sense of serenity again until spring rolls around.
This is the way things are, and the way things have always been. But ... why? Who made this decision? I dream of a world in which ballparks aren't just the places where Major League Baseball happens, but they're also recognized as some of the most unique spaces in America, oases of color and light -- basically parks, except with so much cool stuff built in.
That's why we should start treating them as such, and keep them open 365 days a year.
I know, I know. Most ballparks aren't just empty for the offseason. There are concerts. There are bowl games. There's ice skate racing. But those are just one-offs, single events that require a ticket and, crucially, don't let you actually interact with the park. My proposal is far more elegant: Keep the ballpark staff around, open up the gates and just let people hang out.

Just think of all the possibilities. Hold a giant slumber party under the stars! Construct an elaborate blanket fort in the stands! Organize a home run derby with you and your friends! Your local jumbotron longs for more than six months of Rally Monkeys and train races; it wants to let you play the coolest game of Nintendo known to man. Want to embrace the elements? Let's go ice skating. Love Nickelodeon's 1990s game show heyday? Four words: Double Dare obstacle course. 
Baseball is more than just a game: It's an aesthetic experience, a place to sit back, stare at summer incarnate and let your cares melt away. Why limit that to just six months out of the year? Why should we be denied a picnic in the grass just because it's late January? Why shouldn't I be able to eat a boomstick whenever I want? Baseball is a game by the people, for the people, and the people demand round-the-clock access to enormous novelty hot dogs.
Have your own ideas for how to use your local ballpark over the winter? Let us know @Cut4.