The rebutal was stupid (and self defeating, FreeMoney the coins are only worth something if people want them) but THERE IS an easy solution.

bit-pay.  Very easy.  A merchant can signup in about a day, have no currency risk, integrate with online shopping carts, even accept coins from a mobile phone.  If a merchant can figure out a merchant account (CC) they can figure out bit-pay.

Even without bitpay the currency risk is being massively exaggerated.  How hard is it to send all your purchase coins to an exchange and hit the sell button a couple times a day?  Honestly if a merchant gets only a few bitcoin orders this might be easier/cheaper than bitpay.  Send coins to exchange and hit sell.  The intra-hour volatility isn't that high and volatility goes both ways.    The idea a merchant would sell tea @ $32 USD:BTC and not be able to figure out how to hit the sell button on an exchange for 4 months while price fell to $2 USD:BTC is kinda silly.  Like I said if 1% of a merchants sales are Bitcoin and on average they are exposed to 3% intra-hour volatility we are talking about a rounding error in the cashflow of even the smallest business.

Solutions:
small-business with little bitcoin casfhlow --> manually sell coins or use bit-pay
small-business with significant bitcoin cashflow --> use bitpay or develop in-house hedging
enterprise operation with little bitcoin cashflow --> use bitpay or develop in-house hedging
enterprise operation with significant bitcoin cashflow --> develop in-house hedging

The merchant was uninformed, the OP didn't have the information to inform him but now he does.  Short sightedness on the part of  some bitcoin users doesn't change the fact that trivially easy solutions exist.  There is no unresolved problem, simply uninformed merchants.