BTC difficulty going down

[Yuki1988]

If you divide pool hashrate to greater number of individual nodes, then each node has less.
With less power, nodes need more time to generate blocks. There is now greater number of nodes generating blocks instead that one pool before, yes, but on average I think they all will generate new blocks at slower speed. And diff is calculated from the speed (time) new blocks are generated, not from the total hashrate of network. Total hashrate is only estimated, baased on current diff and, again, the speed of generation of the new blocks.

Epic math fail.

Care to explain?

lol