I would appreciate reading any historical documentation about why minPoolCost was thought to be necessary by the design architects. There is no mention of minPoolCost in any of the Ouroboros research papers. Given how detailed the proofs in the Ouroboros papers are, I would have expected some very detailed reasons for, and calculations about, minPoolCost.
Regarding the first quoted dot point above: I can see how minPoolCost might contribute to Sybil attack mitigation. But, the extensive proofs in the Ouroboros research papers clearly determined that such a parameter was not necessary since their analysis did not include it.
Regarding the second quoted dot point above. I would argue that minPoolCost does not guarantee a minimum budget for pool operators because they will only get this minPoolCost amount if they make a block. And, they can only make a block if they get enough delegation. And, they can only get enough delegation if they offer competitive fees. And, with minPoolCost at 340 Ada, they are unable to offer competitive fees until they get more than 10 million Ada stake. So minPoolCost doesn’t guarantee pool operators any minimum budget, instead it guarantees that small pools will remain uncompetitive and too small to get any minimum budget.
minPooCost of 340 guarantees that delegators must financially harm themselves if they delegate to a small pool.
I agree. A more complex change like this will be more difficult to reach consensus about. If we get sidetracked about such complexities now then we will still be arguing about these problems in another 2 years time. We should make some simply achievable changes now to mitigate the problem and consider more complex changes later.