The sarcasm was delicious. I have to comment about this though:

Except... you can't store the code in files that way. Lispers tend to learn their lesson the hard way, as all code is lost when you need to reboot your computer.

I once interviewed for an embedded systems C/C++ compiler company and they told me this hilarious story. One of their big clients made semi-custom hardware to support their lab operations. This client took advantage of a special feature of their compiler/development-environment whereby you could patch code running on a live system without having to recompile just by setting a breakpoint. It turns out that there was a hard limit on the number of breakpoints you could have running at once though: 65536. This client had exceeded that number and then came begging for them to raise it because they had been making changes to their system in-situ for years and all those changes were gone. The changes only existed in the patched binary; the source for all 65K changes had been lost.

So yes, you do need to be careful about interactive systems, but I've only ever heard of it biting C/C++ users this badly.