The key to this parable is that it is not really praising anyone. It is describing a picture of two sets of imperfect people.
Neither son in the story was the kind of son to bring full joy to the father. Both were unsatisfactory but, in the end, the one who obeyed was better. The ideal son would be the one who accepted the father’s orders with respect and without question carried them out.
There are two truths in this parable. It tells us that there are two very common classes of people.
First there is the person whose profession is much better than their practice. They will promise all kinds of things, but thy often do not follow through with actions. Then there are those whose practice is much better than their profession.
An example, the person who professes no interest in the Church or religion yet they live Christian lives better than many Christians.
The point of the parable is that while the second kind of person is better than the first neither is anything like perfect.
The parable also tells us that promises can never take the place of performance. As one author states it, fine words are never a substitute for fine deeds.
The son who did not go was very courteous to his father calling him “sir” but his follow with action was nonexistent.
The Christian way is in performance not just promise!