Your reason #1 was my main appreciation point for smalltalk and squeak, back in my undergrad CS days. Edit the code for how your ide behaves on the fly? Neat!

Now, lots of tools offer that sort of thing. But back in the day it was really cool.

old 486 slackware 4.0 server I had on a big UPS made it through several dorm/apartment moves without a shutdown. Something like 7 years of uptime when I finally retired it.