For the investor it is only interesting to invest in goods that stay. The economical value of 'immovables' is linked to a supposed long, if not endless lifetime. Even when a building has been worn out for a while it still happens often that tons are readily paid for it. That is how we are saddled with expensive but unhandy and energy wasting buildings. Moving goods are generally not investment products and they can't be mortgaged.
Houseboats are cheap in contrast to a scarce berth, which is often unpayable.
Just like cars they only have a very limited value as 'moving' goods, compared to the parking place in which it stands. If we continue this comparison then future living estates will consist of relatively expensive stands with convenient, easy to disassemble energy-efficient living units. Only after answering this question the correct design-strategy can be chosen. Too often, durability is translated in building for the long haul. Ecological designing is smart designing.