Formosa is the name that was given to Taiwan when it was discovered, and the name it kept up until it switched from Japanese to Chinese rule after WWII (nobody refers to it as Formosa anymore).
I think the key point here is that the meaning of the word Formosa is "beautiful island". However, once it fell under Chinese rule, it largely became the home of many globalizing factories which treat their workers like sh*t and give them crap pay.
So basically my interpretation of the song is...
It's a song against mass production (duh). It describes the lifestyle of those that live and work in Taiwan, and how badly they are exploited and taken advantage of.
But he throws in that line "They don't like that much, cause it's called Formosa" kinda to say "this isn't right, we're supposed to be living on a beautiful, free land".