-- the universe won't wait for you
You know, I don't think the people would enjoy living on experimental cities very much. People tend to not like to take risks.
When people see Magma uniforms they go, "Oh what trustworthy looking people. We should let them extend the land! :3" It's for a political reason that we dress like we do.
Ah but once you get some volunteers- the adventurous sort, the Pokémon world is full of those- to prove it's good and safe, people will take a chance. The move will take some time, but will pay off once the majority of civilization is using the floating cities.
Or possibly 'man why are these young people dressing in such gaudy and impractical clothes?'