Reason #4: Because RoboCop Is As Inspiration To Us All
The best reason for a RoboCop statue is because of all the admirable qualities that RoboCop represents. He always stood up for what was just and right. He was beaten down, but managed to stand back up. He is an inspiration to anyone who's ever been executed by a crime lord before. Some might point out that RoboCop was a tool of a sinister corporation, and thus not the kind of role model we want to hold up for our children. These same people might point out that RoboCop was also pretty casual about shooting all those people in the face and torso.
Fans of the films will of course recall this scene, where RoboCop subdues someone for violating a lawn-watering bylaw.
To that we'd respond that there is another way of looking at it, namely that they were bad guys, and that he was fucking RoboCop. Checkmate, due process. Perhaps most importantly, RoboCop had titanium armor, which will inspire children to study hard and get titanium armor of their own. Out of 23 Western nations, the United States currently ranks tied for last (behind Japan) in number of children equipped with titanium armor. Can we afford to slip any further behind?* To maximize the inspirational value of a RoboCop statue, Detroit should make sure an appropriate inscription is applied to the base. The words of RoboCop himself are well suited for this:
Excuse me, I have to go. Somewhere there is a crime happening.
Do you see how polite RoboCop is? As minimum this statue will inspire the citizens of Detroit to have better manners.
*Almost certainly, yes.
Reason #3: To Frighten Evil Doers
You know that old saying, "dope is for dopes?" Well it turns out to have some basis in reality, and we're not just saying that to fill the terms of a plea bargain.
"This is bullshit. Do you know what satire is Officer Gurdy? We didn't mean a single thing we said in How to Sexually Torture all Nine Supreme Court Justices."
Criminals in general are pretty dim, lacking the ability to not drop out of school or pay for televisions. A statue of RoboCop may convince a few criminals that Detroit is finally getting serious about crime, and actually scare a few of them straight. At a minimum, it may reduce crime in the immediate vicinity of the statue, as lacking formal training in art appreciation, many criminals will not know what a statue is. "A fucking cop made of rock!" we imagine them gasping between breaths as they sprint away. "Holy Shit!"