Nope. It's both.
They are awful because they want to be.
Roster changes were made to ensure awfulness.
Tanking.
We can pick this up next year when they do (or do not) get Lebron.
As bods mentioned, it will be crucial to see who they pick with their lottery pick.
They're awful because management assembled a team of nobodies. Outside of a 41-41 Orlando team (which missed the playoffs), no one has done that with any success. It's not that New Jersey players aren't trying, or that the coach is playing to lose. It's the talent level is that shallow.
Unless they're planning on picking a new owner with that draft pick, it's not going to matter who they get. Unless the management assembles a team capable of winning, they're not going to win.
And if LeBron - against all expectations, advice, history, and common sense - decides to be the future face of the New Jersey franchise, then get ready for a mostly-irrelevant LeBron James.