If CC/Paypal was added, you would have a large advantage over competition and questions of legitimacy would probably fall off substantially.
But then we'll have to fix price in USD, something we don't want to do.
Only initially, whilst you build reputation and trust...
Think of it as an insurance policy due to the volume and frequency of previous scams. People are justifiably wary and don't want their fingers burnt a first, or a second time.
We are willing to trust you, but you need to build it. We're not denying that dollars aren't the favourite medium of exchange, but in this initial instance they are preferred with a VISA credit card 120 day protection.
Also most miners are new currently, don't have the coins mined to pay you, and exchanging is messy right now.
The rationale to not escrow through John K. remains unaddressed. Simply declining to escrow without offering a rationale seems amiss, especially since it would actually benefit you in terms of credibility.
It could still remain in BTC, it would offer buyers a degree of confidence in an unproven product/service and I am sure the small fee that John K. charges is not a barrier to purchasing for those preferring fair terms of trade.