From the research I've seen, eccentric contractions favorably recruit type 11B fibers (if they preferably recruited type 1 fibers, then you wouldn't be stronger in the eccentric portion of the lift). They also have been shown to cause more microtrauma (which is one of the theories by which we believe growth occurs).
Deadlifts still have an eccentric portion though, don't they? With the olympic lifts, you pretty much just drop the weight (usually you are using bumper plates on a platform). With Deads, you don't try to lower the weight super slowly, but you are still controlling it back to the ground.
That could work, but why even do the OLY lifts then? You can gain plenty of strength from more traditional BB'ing lifts, AND produce hypertrophy at the same time.
10-20+ sets, with 20-30 seconds rest, using 60-80% of 1 RM? Have you actually tried this? Because that sounds to me like:
1) your form would go to complete shit
2) you would be greatly increasing the risk for injury
3) you would never complete 20+ sets with 80% of 1 RM with only 20-30 seconds between your sets
In other words, it sounds completely hypothetical, never been tested to see if it would actually work. Either that, or you are drastically underestimating your 1RM (or are some sort of freak, and we will likely be seeing you win the gold medal at the next olympics in weightlifting).
Show me some videos of BB'ers doing DB swings or KB swings who got huge using those exercises. Those exercises can work well for GPP, or maybe even explosiveness in the hips. But from a building muscle perspective, there are better ways out there.