Why are certain NBA teams bad for such long periods of time

There are some NBA teams that seem to be bad for literally a decade at a time. Is there a reason for this? Am I imagining things? Or is it just normal and fine and it just makes sense in a very competitive league where a few players can make a huge difference unlucky franchises can have big periods of time where they just aren't good

[QUOTE=Street Hunger;14969587]There are some NBA teams that seem to be bad for literally a decade at a time. Is there a reason for this? Am I imagining things? [/QUOTE]

Stopped reading here. You are.

Very possible, yes