It's so fucking old already - enough!
Indy IV hasn't happened yet for several reasons, the least of which is scheduling and the fact that Frank Darabont turned in a shit script. Yes, Lucas was busy. He was making THREE FUCKING MOVIES and so was Spielberg! I don't see anyone blaming him! But just because Lucas made a less than satisfactory (to some) addition to the beloved Holy-Fucking-Trinity of films, fanboys lash out at him.
I got news for you friendly! Lucas' bowel movements are 10 times as creative as you wankers will ever be!
Get over yourselves already.