The language design failure that get/set methods are used to monkey patch around is the lack of computed properties.

If you have an object with properties A and B, but later realize that B can be calculated from A, it would be nice to eliminate the class of "Inconsistent A and B Values" bugs from your software, by making B calculated from the value of A. The problem is, without computed properties, that involves replacing the Object.B expressions with Object.getB() expressions, breaking your API.

So Java developers got in the habit of putting getters and setters on everything.