Sean has an anecode of two older houses that are not that great anymore. He has provided a counter example to the "all old homes are better built" claim.
You David have provided an anecdote about your house and used your singular experience to extrapolate to all old homes.
True, we're both relying on (very different) personal experience. But, objectively, no 100-year-old home has grounded wiring, modern insulation, or modern HVAC -- unless someone like David (or previous owner) went through the messy and expensive process to modernize it. To put one more "difficult to change" point -- I doubt just about any 100-year-old home has over a 7' ceiling in the basement. I acknowledge that some of the details of new homes are chintzy, but I just mean to point out that I don't think we've lost the ability to create high-quality homes.
As other have written elsewhere, there's survivor bias in that the lower-quality or neglected homes are more likely to be torn down and replaced. The teardowns we continue to see in most of the metro are still part of that process -- the worse-off homes get torn down, because they're cheaper. The Edina/Linden Hills teardowns may be more of an exception to that, since there are fewer neglected homes in those areas, and because location matters so much more than cost.
Remember, in cases of intensifying uses, that intangible value has to be somehow greater than the measurable societal benefit of allowing actual human beings to live in places with excellent access to jobs and amenities. Is your old growth wood grain and needlessly sturdy roof boards worth that?
I agree -- although that becomes a harder argument to make when teardowns are replacing SFHs with new, bigger SFHs.