You're grossly mischaracterizing the quality of those bigs, especially defensively. Kruger is a guy who has said in interviews he spends almost 80% of his time on defense, and it showed in those Illini teams. They were none of the things I mentioned (late on help, etc. ). Those guys were awesome at defending the paint. Kruger had Arch and Cookie, who were both in the NBA. He also had the insanely tenacious Lucas Johnson, Marcus Griffin, and Damir Krupalija. If that's your idea of serviceable, I applaud your high standards, but strongly disagree.
And yes, the game was much more physical at that time, and there weren't as many 3 point shots and spacing. Bigs today need better footwork and reads in the paint.