Wasn't always like this, till foreign investors started buying up property and renting to those who could afford what they were asking.
As for the homeless, did you not catch the story last night on HNN?  While there are many local families who are homeless,  there's approximately 300 -400 who come from the mainland yearly cause they think its better here then where they're from.  
Fasi, bless his soul, may have been right decades ago, but that still doesn't prove Oahu residents could afford to build it decades ago either.  One thing history does show though,  A council member thought Oahu couldn't afford building rail 20 years ago and voted against it.  20 years later, the city tricked the residents into thinking the city could afford and build rail, and with its soaring price tag, it just proves Oahu still can't afford building rail.