I'm not sure what you mean by "decrepit shape."
As far as I could see, the Revolution had abolished illiteracy, its first major task, and then went on to provide housing, medical care and education to the entire population. The older buildings, apart from tourist icons like the Tropicana, seemed to be pretty neglected but the people were well-fed and cheerful.
The only thing that had me worried was a decline in Revolutionary spirit among the young people, who seemed a lot more interested then in pocket calculators (this was the mid-80s,) blue jeans and rock-n-roll tapes than in building socialism.
Maybe there's a propaganda failure. And leadership, since Fidel really hasn't tried to bring dynamic young Communists in to carry forward the next wave of socialist struggle. It does have the look of a self-perpetuating oligarchy, and there is nothing Revolutionary in that.
So getting back to my first question, why "decrepit?"