Let me give you a scenario. I go and create this type of pool, and have 2 miners connected to it. After a while the first block is found by miner 1. Both miners have been submitting work equally. I have 25BTC to give out. Who gets it? If I pay miner 1 the full 25BTC for finding the block, I don't have anything left to pay miner 2. If I pay both miner 1 and miner 2 for the work they've done, I don't have the 25BTC to give to miner 1 for finding the block. Make sense?
Just to tweak your scenario to suit my utopia.
2 miners connected, hashing equally.
Scenario 1: Miner 1 finds the block - Miner 1 gets 25
BTC less the mining fees attributed to Miner 2's work which Miner 2 gets
Scenario 2: the pool wins the block - Each miner gets 12.5
BTC including (or in addition to) the mining fees attributed to their work submissions
I think I found your confusion. There is no such thing as "the pool wins the block". Either miner 1 or miner 2 had to have solved the block. Your scenario 1 is in reality your scenario 2, minus that "pool wins the block" stuff. If both miner 1 and miner 2 are mining with equal hashing power and equally submitting shares, then they've each contributed exactly half the work necessary to solve the block. Therefore, they're each going to get 12.5
.