then in the uptopian dream of zero greed, bitcoin can be used for microtransactions without a large cut.
if mining pools would simply just accept transactions into blocks instead of ignoring them all the time, there would be no issues.
The amount of tx's that can go in a block is limited right now (well its by MB but thats essentially the same). Additionally full blocks DO take noticeably longer to propagate the network and do increase the risk of the block orphaning. Some miners take the risk and include free tx's for altruistic reasons, but most miners are running a business and they are not going to risk their 25BTC reward for free.