Maybe it's little-used because the surrounding neighborhood is bombed-out?

If the population is down like 60%, it stands to reason that the park will not be heavily utilized relative to past years.

It's also an open question whether these parks are even needed nowadays. Almost everyone in Detroit has a yard of their own. This stands in stark contrast to many other big cities. The purpose of such parks then shifts to sports/fitness, picnicking/bbqs and the like, and I don't know if this park has such amenities.

And, of course, there could be safety issues, or at least perceptions of safety issues.