It is not my intention to insult anyone, but is there a reason why people do not paint the outside of their properties? Growing up my dad used to say that by looking at the outside of a home, you will know how it looks inside.
Even if a house is old, painting it can make such a huge difference. I find that most buildings are so ugly.
I can’t answer your question (although I guess it’s due to humidity and mould), but your dad is unbelievably wrong. I’ve seen so many homes that look like crap on the outside but are amazing inside. This might be because I live in London where even ugly former social housing is very expensive. People make do with what they can.
It’s common in Taiwan, build it and never maintain, even inside. Wait until the old generation dies, then it’s time to renovate with the money you get from an inheritance. In the many years I’m in Taiwan I’ve seen few people redecorate a home. They just do the whole renovation thing after 30 years or, rip out everything and spend another million or two renovating.
Sometimes it’s ownership issue. As in the building is owned by different owners. So who’s going to clean the outside? The management. Often the management fee barely covers elevators, security, etc. and unless they increase the management fee by a lot, they can’t power wash the walls every other month. And also on that subject, those mold builds up rather quickly. So people may just feel it’s no longer worth the trouble.