I guess by real world usage I mean what proportion of code is being made with them. You should be skeptical of their accuracy, but there are measures for that. Like there is this one: https://www.tiobe.com/tiobe-index/, but it describes it's methodology as being about popularity based on articles, news, and other such things. Github publishes a very different chart as does RedMonk. Rust barely shows up on these charts, but Rust fans are very enthusiastic in threads like this. I like Rust well enough, but I also find the over-enthusiasm amusing.

By practical/pragmatic I mean the ability to target a lot of hardware with C. Sometimes the tooling is crap, but it's very universal. Being built on LLVM Rust can go onto plenty of hardware too, but it's probably not the tooling given to you by a platform vendor. It's also been around for a long time, so using Rust would mean a rewrite. Sometimes C is simply the choice. As for ideologically: Rust solves some pretty nasty programming issues, but sometimes I think it's fans over-estimate the percentage of real world problems it actually solves while ignoring that Rust can be more expensive to write. (shrug) Sometimes there's no such thing as a silver bullet.