The surviving craftsman homes, which weren’t average for the time time due to survivorship bias, are more likely to be built in higher density walkable environments closer to urban cores. Real estate in those areas is more valuable in general.

The average D.R. Horton home is built further out on lower density, less valuable land.

There’s also an element of scarcity here. There’s a subset of people who find older homes appealing specifically because they are older. The supply of older homes can’t increase, but the supply of D.R. Horton homes can and does.