Of course Charity demands that the Church care for the physical welfare of the poor. That is why we have Missions, Church charities, and so many Religious, and indeed laity, who devote themselves to this work. There is, however, also a reason for the Church to possess and care for things of beauty.
Nowadays, we hear a great deal about the importance of a pleasant environment and its effect on health and wellbeing. The Victorians recognised this when they included public parks, statues and imposing civic buildings in industrial towns. It is the reason why today's councils are tearing down depressing estates like this...
... and replacing them with this sort of thing.
We who work in education are very aware of making classrooms pleasant, interesting and stimulating, and devote a lot of effort to keeping rooms tidy, putting up displays, and so on.
It makes sense, therefore, for the Church to provide places and things of beauty which help to inspire and to develop our awareness of, and focus on, the divine. This is especially true of the poor: if the only beautiful things you see in your life are when you go to church, then these will be things you value greatly. I am always aware of this when I visit Medieval Cathedral Cities. Here, for example, is Canterbury.
It isn't hard to imagine this street in the Middle Ages when it was built - dark, squalid, an open sewer runnin down the middle - but in the distance a glimpse of the magnificent Cathedral, inspiring thoughts of God, and hopefully the reward of Heaven. When the citizens went to Mass on Sunday, perhaps they saw something like this...
...the most beautiful thing this side of Heaven.
Yes, the Church should care for the physical needs of the poor - she does - but she should also care for their mental and spiritual wellbeing, and one way to do this is through great art and beautiful buidings. After all, being warm, healthy and adequately fed, but in a totally barren an soulless environment doesn't make people feel paricularly good or happy.