But developers with good tooling to deal with more static views of the code aren't the only readers of SQL, and perhaps not the most common.
With my DBA hat on, trying to figure out what's going on reading through logs and such, I don't always have that kind of tooling available. In this context the casing can help as well.... and this may form some of my bias; my first professional experiences on the application side of the world were in very much DBA roles dealing with other people's applications running on my servers. Insofar as access tools preserve developer formatting, having good "color-blind" formats made reading complex queries easier.
I wonder if programming languages should have a way of specifying that a string constant contains embedded code or a template, so text editors can display it accordingly.
I deal with a lot of SQL embedded in code, and prefer uppercase keywords as it seems to help me visually parse the overall file.