History does not seem to agree with you. There were memory safe(er) languages before Rust existed, and OSes written in those languages. Neither became popular.
Besides, there are many many factors determining successes of OSes, often far removed from quality of the software itself (1986 AmigaOS had GUI and multitasking, and still lost to MS-DOS and Windows 3.1).
Either way, general grumpiness about Rust being used to write an OS may be a reaction to the hype, but plenty of people have expressed interest in an OS written in Rust, if not for any other purpose than to challenge Rust's basic claims.