Experience. "Bitcoin transactions are instant - the confirmations aren't. It usually takes less than an hour for the first confirmation." There is no such thing as a "low value" transaction... Milk is NOT free and if buyers use bitcoin you are asking the merchant to risk being robbed... else hold his customer for an hour.
It will be long before we can expect people to use Bitcoin for groceries, but setting this aside, given precautions I mentioned few posts above the risk becomes largely mitigated and acceptable for low-value transactions (I can be struck by a lightning any time I am outside, does that mean I shouldn't leave my room?)
Are you sure it's worth it?
It's CERTAINLY worth having a discussion, yes.
I wasn't clear enough, discussion, sure, but do you really believe it's worth to design & build an ASIC for scrypt in the foreseeable future?
We are seeking engineers and mathematics, coders and builders.
only those with the best economies of scale will remain in business with profit margins decreasing.
As a "rich American" I find this logic flawed. People who cannot (or will not) afford ASICs will STILL want to mine. Crypto Currency is about MASS adoption. If only Vlad is mining then everyone else will migrate elsewhere.
Gold is used widely in the world and people still use it despite the fact that only a few can afford to mine it themselves (nothing stops people from buying it). Bitcoin will someday (hopefully) become widely used like paypal but already now people who use Bitcoin actually buy it (or offer goods/services for BTC) because not everyone wants to bother/can afford/has time/is technically knowledgeable enough with setting up a mining operation (like with gold). Bitcoin, like gold, is used due to its advantages over fiat, not because ''it's a money-making machine''. The ''money'' part is only there to secure the network, Bitcoin is about financial independence from the state and middlemen.