One thing that your completely missing, however, is that people leave their phones on most of the time. Encrypted drives only work effectively if your system is turned off at the time it was stolen.
That's why I don't bother with it on my laptop, except I store some of the more sensitive information encrypted via encfs and cryptkeeper. You see: I leave my laptop on all the time. Even when traveling it's suspended. Out of any modern device it's fairly trivial to pull encryption keys out of memory. There are ways it can be mitigated, but that is not the reality we live in right now in terms of hardware security.
But there is not much on a phone that I would tolerate using if I had to type in a password every time I needed to access it. Usability easily trumps security in this regards.
Remote wipe is really a pretty good way to keep your stuff safe. Cell phones are stolen very often, smart phones are even more attractive targets. People frequently leave their phones laying around and forget them in public places. People leave them on all the time.
If I was a business type guy buying phones for my employees then it would be a invaluable feature.
For my personal use it would be a invaluable feature.
The problem is not that there is a remote wipe. The problem has to do with who is the one in control of it.
That is true with most stronger security schemes. The problem is not that they exist or that they are effective or that they can get used... the problem is the people who have the ability to use them. That is: somebody other then the property owner.