Versatility of the standard library and ability to write terse programs which achieve a lot. Even if C++ compiled always in under 0.1s, I wouldn’t call it a scripting language, because its standard library is anemic and basic stuff, like finding things in containers, copying things from one container to another, basically anything involving iterators requires such elaborate code that it’s on the opposite side of the spectrum from a scripting language. A scripting language is a tool for quickly performing one-off tasks. Terseness and a rich stdlib are virtues here.
A scripting language and a compiled language are not two distinct things. A scripting language can be compiled if so desired, and JavaScript does so in most browsers for example.
The main difference between a scripting language and a non-scripting language in my opinion is that a scripting language is called through a host program, which offers configuration and a standard library, while a non-scripting language runs by itself, using the operating system as its environment.
I noticed a lot of disk activity once and fired up Process Monitor (on Windows). Dropbox.exe was going through literally all the files on my computer. That was when I uninstalled it forever.