Nothing at all wrong with them, one of the best rep schemes around for the right lifter.
Some lifters are doing 5 x 5 on MP with 25kg, that is a waste of time.
20 rep squats is the greatest mass and strength builder for novices.
High rep squats in general are better than low rep for lots of lifters.
On bench press 5 x 5 works extremely well, deadlifts and powercleans work best with 2-3 reps.
This can get complicated for the novice lifter, so Bill Starr simplified, his original program was for high schools, generally teachers instructing.
I think the results of my 17yo son shows that my method is more effective than starting strength, compare numbers/bodyweight/experience against the owner of that sight, Max destroys him at 17yo.
For the novice lifter uncapable of using an assortment of reps and sets and is happy to keep it simple, use Bill Starrs 5 x 5.
But if youre after the best results, there are better ways, much better ways.