You are wrong, you can perfectly apply for non-o outside the country, so I am waiting for the first one of your list from many types of visa that can be only applied from inside the country as you say...
Worldwide the normal way to apply for a visa is from outside the country because it is the way to get into the country.
Please mention them, I know you can convert some visa to other visa, and also can convert a visa exempt stay to a visa sometimes, but in general you apply for a visa outside.
normally you don't apply for a visa in a country, but outside, and it will not bring you in contact with immigration. When you enter the country you will have contact with immigration, but that has nothing to do with the visa application process. Immigration is not deciding about the visa application process.
The changing is annoying, but made necessary because heavily misuse, which is caused by having loopholes in requirements. For some reason it is difficult for Thai to look already and predict what will happen. The change of visa exempt from 30 to 60 days was made to get tourists stay longer. The average tourist from western countries stayed about 2-3 weeks, Asian tourists did stay 1 week on average. So 30 days was more than enough, the change to 60 days would not get more tourists, but would make it easier for people who wanted to live in Thailand without visa. The DTV in itself is a good idea, but there are too many loopholes.
I think a lot of digital nomads not stay over 180 days a year in one single country, that is what it means to be a nomad. And yes, I know a lot of people here want to use the DTV just to live 5 years in Thailand. If and how Thai authorities try to change rules to prevent this not intended use, time will tell.