[David.Cook]

Why is KOH not so successfull? I think the strategy does not yield enough QP.

In the one scenario given (which assumes everything works perfectly) you get there first, get all the bins and completely lock down the hill. So the opponent has 16 pts and you have 25 + (4*33) = 157 for 189 QP. Sounds great, eh.

Not so fast...
first you are depriving your alliance of 125 QP. If you really have all the bins and your 4 stack, then you actually want the other bots to get on the hill - those are QP's! You get 2*25 for every bot you let on the ramp. you also get 25 QP for your partner.

Still too fast...
about 50-70% of the bots get under the bar, so if you are stuck blocking the top, then it is almost a foregone conclusion that your stack is gone, because the other bots will go ballistic, they will spend 1:45 clearing out your area (we have all seen this in action) leaving maybe 5 or 6 bins. Now your fantastic score is 31 to 16, leaving you a wopping 63 QP.
[I checked and at NASA/VCU the average QP was 78]

Whoa Nellie, slow it down some more...
OK, the world ain't perfect, so let say just four bins dropped behind you as you crashed the stacks. Now the opponent actually has 4*8=32 pts to your 31!! Uh oh! They end up getting 93 QP.

Evasive action, immediately...
Now you find yourself leaving the hill to attack stacks or clear bins from the opponents scoring zone. So much for KOH as a sole strategy.

Disclaimer:
Yes, KOH and the 25 pts associated with it are VERY important. So important that there are times when you have to consider whether it is better to let your opponent on or not, or even decide whether you should get on or not (if you are losing badly). However, we are seeing in practice that you need not block the ramp to win, but you better be able to get there and stay there when you need to.

Thanks for letting me ramble a bit.