Enormous car-lots several times larger than the buildings that they serve for example, sprawling 6-lane roads that take 20s to clear a junction on a slow moving bicycle, these things contribute to it being infeasible for more poeple.
Connecting the bike lanes is not a problem, though people will fight it tooth and nail because they wan't all infrastructure spending to go to cars... hence, reinforcing the issue, because when all you have is a hammer...