Well, number one, man doesn't live by bread alone. He needs spiritual sustenance as well. Cathedrals provide it.
Number two, the great cathedrals were built at times when many people volunteered to work on them and others did so because frankly, they needed a little extra cash. Unlike the famous pyramids of Egypt and Mexico, which the left-wingers love so much because they were built by "cool" pagans, no slaves built the great cathedrals and churches of Europe and the Americas. Many artisans made a good living and a lot of serfs got a few bucks in their pocket to take to the next fair, thanks to time spent on the cathedral construction crews.
Number three, in the days when those cathedrals were made, the towns that made them were prosperous. The size of the temple indicated the wealth and community pride that the town had, much in the same way that Italian and Irish and German and Polish immigrants in the U.S. competed with each other to see whose church would be the biggest in many big East Coast and Midwestern cities.
http://en.wikipedia.org/wiki/Polish_Cathedral_styleSince the days when the grand churches were built, Freemasonic and Socialist experimentation and wreckovation of national and local economies have caused many of the inhabitants outside of the cathedrals to fall into deep poverty. This is the phenomenon you are reporting in your post. Remember, the impoverished beggar of today was not the craftsmen or stone-hauler of yesteryear who actually worked on those edifices.
Number four, "give a man a fish and he eats today. Teach him how to fish and he will eat every day." What good would it have done to take the money used to finance the construction of those beautiful churches and give it to "the people"? In a few weeks or months "the people" would have spent it on useless crap, either beer or baubles, and would have been left off worse than they were before. At least these churches gave them a dignified place to worship and a sense of pride and achievement.
These great cathedrals are tremendous artistic successes and tributes to man's supernatural faith in God. If they didn't exist, would the world be a better place?