You asked for reasons against the idea, but what is needed is reasons for the idea. It doesn't solve any problems with the bitcoin system, so there is no reason to implement it.
No. Complete misunderstanding between us
I asked for reasons against the idea - but I never intended to implement this. Remember the disclaimer at the beginning of my post? I really meant that disclaimer.
My approach is the following: Whenever a program has to solve a certain task, you will end up with a specific implementation. Some of it's properties will be must-have properties (For example: Bitcoin would not work without some form of randomization. There is a proof on the complexity of deterministic consensus algorithms, which applies here, and which tell us that Bitcoin would not work without a random or pseudo random element in it.) There are other properties, which are nice-to-have or plainly coincidental. Currently I am trying to understand, which parts of Bitcoin are must-have and which parts of the algorithm could be different. If I have answers on this I can come up with different algorithmic schemes. That's the way I do research (which is the way I earn my living) I am into thinking, not into minting - and hopefully this may prove useful after all
Well, I get more pleasure from "ThinkCoins" than from Bitcoins, I guess
About this orphan block thing. I realize that we need some incentive for miners to work on the most current block. The variant I suggested could enable malicious miners to obtain bounties by only producing orphaned blocks, which is not what we want. Therefore my original concept must be modified a bit - as I wrote in my post - by placing bounds on difficulty or depth. Currently we are seeing miners minting blocks without any transactions all - which could mean that the current implementation has a small incentive-loophole, given the conditions under which these miners (bot-nets ?) operate. The interesting question thus is: WHAT are the minimal conditions we must require for the bounty to work properly?
Orphaned blocks are not a problem. If 1% of blocks are orphans, it just means that the difficulty will be 1% lower, and miners will on average get just as many bitcoins despite the occasional orphaned block.
That is a great way to put it and this comment helps me a lot. We actually can model this part of the algorithm as difficulty (probably not lower but higher, if we take expected payout as constant in our model).
So, let us assume we have a percentage p of orphaned blocks. Now, let's assume we increase block chain speed. This has been discussed in the forum (and it would increase the number of orphaned blocks). According to your idea it would mean different difficulty. So a next question is, whether there are still other aspects in addition to different difficulty...