Sounds like nonsense to me: if you buy 1 BTC from me, then at the same time I've sold 1 BTC? That makes it by definition as equally hard (or easy) to buy as to sell?
That would imply there are currently more people wanting to sell an IPhone 3G than people want to buy it. Certainly the price of IPhone 3G's isn't rising. And that makes sense.
Currently (and for the last years), the price of BTC has been rising implying that's actually easier to sell BTC than to buy? Moreover there are exchanges that are entirely symmetric (when opening accounts you do not need to qualify as a buyer or seller).
Asymmetry is a nice word but I don't see what's asymmetric here?
I'm not familiar enough with Bitcoin to engage in dialogue about its market dynamics specifically. I only wanted to point out that the mere fact that all sales involve both a buyer and a seller doesn't make it "by definition as equally hard (or easy) to buy as to sell".
Try buying an iPhone 3g right now on Craigslist. I bet it takes you all of two minutes.
Then try selling it. I bet it takes quite a bit more time.
Asymmetry.