While I find this beautiful, I've always found it difficult to accept such allegory. Some of the ECFs really abide by this as the highest interpretation, but I'm just not convinced that it is. Frankly, I'm kind of glad it went out of vogue. Seems too forceful.
It hardly went out of vogue: with some variations in the details of the explanation, this is how almost every liturgical tradition I'm familiar with interprets the parable in its hymnography. For instance, for the fifth Sunday of Lent in the Syriac tradition (a loose translation):
When Adam had fallen [by the wayside],
None of the Levitical priests or the prophets came to his aid.
The Lord of the Prophets [however] came and raised him up,
Bandaged his wounds, gave his body and blood
As a deposit for his care, and placed him in the care of his Father.
Lord, who (sheltered me in/protected me by) your grace, glory to you.
Even in the Gospels, some of the parables are quite obviously allegories about his saving economy, and all of them reveal this economy in some way, so it's hardly "a stretch", even if a given parable may also have a more "practical" application.
If this is too forceful an interpretation, what do you think the true interpretation is?
It is rather straightforward in it's simplicity compared to say the wheat falling in different places parable.
However there is nothing wrong with the above usage IMHO.
But Christ also made plain the meaning here,
The Sheep and the Goats
31“When the Son of Man comes in his glory, and all the angels with him, he will sit on his glorious throne. 32All the nations will be gathered before him, and he will separate the people one from another as a shepherd separates the sheep from the goats. 33He will put the sheep on his right and the goats on his left.
34“Then the King will say to those on his right, ‘Come, you who are blessed by my Father; take your inheritance, the kingdom prepared for you since the creation of the world. 35For I was hungry and you gave me something to eat, I was thirsty and you gave me something to drink, I was a stranger and you invited me in, 36I needed clothes and you clothed me, I was sick and you looked after me, I was in prison and you came to visit me.’
37“Then the righteous will answer him, ‘Lord, when did we see you hungry and feed you, or thirsty and give you something to drink? 38When did we see you a stranger and invite you in, or needing clothes and clothe you? 39When did we see you sick or in prison and go to visit you?’
40“The King will reply, ‘Truly I tell you, whatever you did for one of the least of these brothers and sisters of mine, you did for me.’
We are told directly to care for the sick and needy and those in prisons, whether they deserved it in our opinion or not.