The poor you will always have with you

There is certainly a criticism of Judas' attitude in the verses, but the Church interprets the verse as applying generally as well. Catholic teaching, as well as the teaching of most Protestant churches, does not normally use these verses to justify ignoring the plight of the poor. Quite the contrary the Church Fathers frequently stressed the importance of helping the poor financially:

Origen, for example, harshly condemned churchmen behaved as Judas did:

Judas appeared to be concerned about the poor... If in our own day some hold the purse of the Church and, like Judas, speak out for the poor, but then take out what they put in, let them share in the lot of Judas.” (Commentary on the Gospel of Matthew, 11, 9)

Also:

• St. Cyprian devoted a complete treatise to the issue.
• St. Basil recounted a story of how St. Lawrence distributed the treasures of the Church to the poor.
• St. Ambrose lauded the breaking and selling of sacred vessels for the redemption or captives.
• The Fathers also taught that the wealthy are God's stewards and dispensers, so much so that where they refuse to aid the needy, they are guilty of theft (St. Basil, St. Gregory of Nyssa, St. Chrysostom, St. Ambrose, St.Augustine).
• St. Cyprian asserted that adherents of other religions must not be excluded from a share in Catholic charity (De Opere et Eleemosynâ, c. xxv, P.L., IV, 620).

Source: Alms and Almsgiving in the Catholic Encyclopedia.

Pope Francis has gone even farther. Writes Bishop James T. Schuerman:

When Jesus says, “The poor you will always have with you,” he is not dismissing poverty as an inevitable reality, but rather making a contrast between the continuance of the presence of the poor, and his own fleeting presence in this world... Pope Francis writes, “It is not a question of easing our conscience by giving alms, but of opposing the culture of indifference and injustice we have created with regard to the poor.”

While it is true that this gospel also discusses the idea of spiritual poverty, that interpretation does not work here. The context is clear that both Judas and Jesus are speaking about the issue of money:

Judas Iscariot, one of his disciples (he who was to betray him), said, “Why was this ointment not sold for three hundred denarii and given to the poor?” This he said, not that he cared for the poor but because he was a thief, and as he had the money box he used to take what was put into it. Jesus said, “Let her alone, let her keep it for the day of my burial. (John 12:4-7)

The OP states: "the more accurate (or at least equally acceptable) interpretation of the verse would be a damnation of Judas as opposed to a guarantee that the financially impoverished are a permanent characteristic of reality." It's true that Jesus is responding to Judas. However, the term "damnation" is too strong. Judas would be damned by his later action of betraying Jesus not for objecting to the supposed waste of money above. Thus Jesus declared:

woe to that man by whom the Son of man is betrayed! It would have been better for that man if he had not been born. (Matthew 26:24)

Since the OP asks for answers from a Catholic perspective, Judas was also damned by his later action of taking his own life (Matthew 27:5). The Catechism affirms:

Everyone is responsible for his life before God who has given it to him. It is God who remains the sovereign Master of life. We are obliged to accept life gratefully and preserve it for his honor and the salvation of our souls. We are stewards, not owners, of the life God has entrusted to us. It is not ours to dispose of. (#2280)

Jesus did not condemn Judas for criticizing the supposed waste of money. He used the situation as a "teaching moment." More to the point of the OP question, while Jesus did address Judas in the verse, the teaching was general, not for Judas only. It does not refer to spiritual poverty but to poverty in the financial sense. Catholics do not understand these verses as a justification to ignore the suffering of the poor, even though the poor are indeed still with us and may always be. Rather, the Church Fathers often referred to these verses to emphasize the importance of almsgiving both by individuals and the Church as an institution. More recently, the pope encourages the faithful to "oppose the culture of indifference," as well as to help the poor directly.