That piece seems very fair to me. I agree with almost everything he said.
The only part I disagree with is the part about scaling. He's making it sound as if there's some kind of hard limit built into the protocol's basic design. But things like the block size can be easily adjusted as needed in the future. In fact, I believe it already went through a number of size changes. Also, the block size is there for more than just priority. It's also a way to make sure that mining happens even after all the Bitcoins have been mined. The block could easily be made huge in size to fit all the transactions. But that would leave little incentive to add a transaction fee. The limited size gives people an incentive to add that fee, so that mining can take place, and the network kept secure.
This line specifically doesn't make much sense:
"For example, it’s hard to imagine Bitcoin ever becoming a replacement for conventional credit cards. There are far too many credit card transactions for the Bitcoin network to accomodate."
Two things. First off, like I said, I believe the block size can be adjusted so that, relative to however much mining happens, the network could indeed handle as many transactions as credit cards.
Second, that's not even necessary. Credit cards are just that, cards that hold the information for your credit with some company. A credit card doesn't store any actual currency on it. If I have a $10,000 Visa card, it means I can borrow up to $10k from Visa. And since Visa is much more reliable than me, a merchant has no problem accepting it as payment as opposed to a personal check from me. Visa pays him, and I owe Visa. The whole deal is denominated in USD, or whatever currency really, but it could just as easily be denominated in Bitcoins.
There's no reason why in the future a Bitcoin-denominated credit card cannot exist. Call it the John card. I'll be an intermediate between my customers and the various vendors. Since I'm more reputable than my card-holders (on average), merchants will have no problem accepting payment from me. So someone could go to the store with a John-card, pay the store with it, the store will get their Bitcoins from me, and I'll get them from the customer. Done deal.
In fact, the whole thing could be handled virtually first, and the balance closed each month. So the actual transactions would all be off the Bitcoin network. Then once a month everyone settles their debts by transmitting Bitcoins, and that gets broadcast onto the network. This would cut down on network traffic for each transaction.
Your post was very good, and agree. I don't think we will ever get rid of the 'instant' or 'revokable' payment methods for consumer purchases, there are just too many upsides to it. People also like to spend more than they have, so VISA will indeed have a place in the market, settling on an interval period.