Because the StackOverflow survey which Rust keeps winning defines "Most Loved" as:

> % of developers who are developing with the language or technology and have expressed interest in continuing to develop with it

Because there aren't that many Rust jobs, almost no one has to use it. Which means people either try it and leave, they like the language and stick around, or they never use it (the overwhelming majority of developers). This leads to the Rust being the most loved language by the above definition, which is completely different from "popular" (as in the title of the OP).

If I make up my own language that I plan to never stop using, even if no one else ever touches it, I'll get 100% "Most Loved" on StackOverflow's survey.