Perhaps for you, but average Joe does not know, nor care how to do this. I've worked with "technical people" who couldn't figure out how to use PGP to encrypt emails, imagine trying to explain to random people what a VPN is.
As long as signing up with gmail stays easier than hosting your own email, nobody will ever bother - and this is the danger schneier is talking about.
On that note, is there a down-to-earth guide to setting up your own e-mail host?
Setting up an SMTP daemon and IMAP/POP3 server is rather easy, the most difficult decision being which SMTPd to choose (I like Postfix, but Exim is Debian’s default and hence supposedly good as well, others like Courier) and then reading the relevant manpages :)
If you search for, e.g., "Postfix tutorial", you'll find plenty of reasonably good guides.
Then again, you have to worry about redudancy. How would you feel missing an important email, due to your VPS/Dedicated server being currently ddos'ed or unreachable for other reasons.
In addition, do not forget about backing up.
So, that again is in no way "easy 1 hour" task, especially for those who are doing it first time.
At which point all your data is up for grabs by your VPS provider?
I host my own mail (for values of "my own" where mail server is hosted on a vps on a foreign server), but I think it's a stretch to say it's trivial to do so.
I think one of the most serious problems the Internet is facing is the growing split between "servers and hosts" and "consumers and clients" -- and the asymmetric bandwidth (both adsl and cable). It favours designs that are centralized, not because of sound architectural reasons -- but because of inferior infrastructure.
I think it's safe to say he was referring to the 99.99% of internet users for which his statement is true. Sure, he's generalizing a tiny bit, but it's basically true.
You can make it accessible anywhere with a smart phone. You can back up by encrypting the data with a public key and sending to a drop box type service; with the private key stored offline. Most web apps could be easily replicated by storing the data in an append only structure with timestamps. The internet then just becomes a messaging system.
I think the VPN tunnel approach should be pushed by everyone. Lots of companies could secure most of their communication by creating a few tunnels to key clients. Email would be immediately secure without any PKI.
For someone to be successful in 1993 to use the Internet, you had to be knowledgable enough to do the things you're talking about. I'd wager roughly 97%+ of the population is not smart enough, which is why Bruce's statements are in effect true.
A few years ago when I ran my own mail server, having only one false negative was a good day. Google can throw teams of people at the problem.
It may interest you to know that not one piece of intercompany email at rsync.net has ever traversed any network. It's all just a local copy operation.[1] So, no encryption, but ... that's not relevant in this case.
The same could be true for your family, or small social circles that share an email server. If you use a secure mail client to connect to the server, and all mail on that domain doesn't traverse a network ... that's a win, even without "email encryption".
That's not a given. Not only is it trivially easy to host your own email, there are a number of very positive side-effects of doing so. For instance, when I email my wife, it's just a local copy operation - no network traffic is generated, and thus nothing can be intercepted by third parties.
Further, although I have not done it yet, it appears to be only slightly more technically challenging to provide your own dialtone.
In 2013 the Internet traffic I actually do generate is much more secure than the Internet traffic I generated 20 years ago. Now I have a VPN to various endpoints around the globe. That's much better than telnet to tc.umn.edu :)
The disconnect here is that he is talking about particular consumer properties (walled gardens) that happen to exist on the Internet. It surprises me, given who the author is.