I assume Pomeroy's blog series on offense vs. defense is what was referenced by the Illinois site. The summary is linked below.
It's accurate that he finds that offenses have more control over how much they score than defenses do. He finds that about 64% of an offense's points per possession are controlled by the offense rather than the defense. But of note, turnovers (steals, particularly) are one of the things that defenses have more control over. He also says, "the defense's tools are two-point defense and influencing shot selection." The latter of those is what Iowa State generally tries to do, forcing a team to take uncomfortable twos and take more threes than they would ideally like to.
I definitely think there's something to your point,
@RezClone, that Otz's defense is more about dictating than most. They make it very easy for the offense to go the places that they'd like the offensive players to go (the baseline, for instance) while using hedging and double teams to keep offenses from doing what they usually do (using ball screens to get to the rim, for instance). Another small example is how it's very common for Iowa State to show a zone defense coming out of a timeout because they know that the offense may have drawn up a play, and playing a zone usually forces the offense to scrap that play.
That all being said, if the offense is making tough shots, which Illinois is capable of doing, the defense can't do much about it. That's where a lot of the offensive control comes from.