"You can't stand in the way of progress."
How many times have heritage preservations heard this? Apparently many people still think progress consists of substituting new buildings for old. Well maybe, sometimes, depending on the buildings. But most of the time, no. There are many reasons for preserving older architecture, like...
Heritage buildings reflect the individual styles of countries, cultures, or regions. Modern architecture reflects globalization. Oh, sure there are some interesting modern buildings in the world. But most of them don't exactly reflect local building traditions.
While public buildings sometimes show a little originality, most new domestic architecture is a bore. Sometimes it seems there's a plot to make entire cities and countries look like this, or, horror of horrors, this. Would you be able to tell the difference between a new house in Toronto, a new house in New Zealand, and a new house in England? They all look like Masonville McMansions.
Modern architecture is science. Old architecture is art. Art is more aesthetically pleasing than cold, impersonal science. It's amazing how often beauty isn't in the eye of the beholder.
Old architecture is human-sized and welcoming. New buildings make one feel puny and insignificant. Compare London's old and new courthouses which are the 2nd and 4th pictures on this link. Of course we need larger buildings today - we have more people than we did in 1829 - but there's something cosy about our colonial past. Kudos to the County of Middlesex for preserving the Old Courthouse, our own little castle.
Visitors like to look at interesting old buildings and it's hard to do that when they're not there. Heritage means tourism and tourism makes money. Look at Niagara-on-the-Lake. A giant live-in museum is a cash cow. Let's try milking the cow here.