1. There is nothing stopping you from lending out your kindle.
2. The notion of "lending" doesn't really apply to electronic books. Absent copy protection, you can just give someone else a copy. With copy protection, to mimic "lending" some infrastructure needs to be in place to give someone else access rights to a copy of a book while simultaneously depriving you of your copy. And of course this is controlled by the seller, since they're the one putting the copy protection in place.
3. I can't copy/paste from my paper books either, at least not in any way that's not also available to kindle owners.
4. Every choice involves trade-offs. There is no morality involved here, much less the sound of jackboots. There is only what people value. Many seem to value the convenience of having their whole library in a small device over the ability to "lend" individual electronic copies. Those who feel differently can stick to paper books, or electronic books unencumbered by copy protection.