Exactly. The contradiction.
It depends on how you look at it. I don't really look at it as 6 days a week because
Mon Legs
Tue Push
Wed Pull
Thurs Rest
Fri Leg
Sat Push
Sun Pull
Mon Rest
Tue Legs
Wed Push
Thu Pull
Fri Rest
Sat Legs
Sun Push
So, look at that second week, you'll be getting 2 days of rest, so it's never ALWAYS 6 days a weeks. The way I see it, every "cycle" has 4 or 5 days. Those days are independent of what the day (Mon Tues Wed) actually is. My cycle is Legs Push Pull Rest. But, if my body needs it, it can then go to 5 days and become Legs Push Rest Pull Rest and then begin again. I go by how the body feels and the body will know if you need to rest or not. I will always do a rest session after Pull, but I can add others in if I need it.
Also, the way of looking at it is that when you're hitting your chest and shoulders, you're also resting your legs that day, so your body parts are getting rest time due to the grouping, which is the essential part of it. When you're deadlifting, you're not working your chest and triceps, so they're getting a rest that day, too. Same when you hit legs, you're not predominantly working biceps and back or traps.