Designing new software is orders of magnitude more difficult than iterating on existing software
Who actually is nagging people multiple times per day to do free labor for them and rewrite a project in a completely different programming language?
That is, nobody perceives, say, "the silver searcher" as being some sort of nefarious plot to re-write grep, but they did with ripgrep, even though that's not what it is trying to do.
There are a few projects that are deliberately doing a re-write for reasons they consider important, but they're not "just because it's in Rust," they're things like "openssl has had memory safety issues, we should use tools that eliminate those" or "sudo is very important and has grown a lot of features and has had memory safety issues, we should consider cutting some scope and using tools that help eliminate the memory safety issues." But those number of projects are very small. Heck, even things like uutils were originally "I just want to learn Rust" projects and not some sort of "we must re-write the world in Rust."
I have a suspicion as to why this perception exists in the C++ crowd.
I don't think it's because of evangelists. C++ was that evangelized language in the early 90's, but after a period in the sun it then survived the evangelism of Java, Python, Go, and others, despite losing ground to them in general purpose tasks.
And that's because all of those other languages, while being much safer than C++, came at the cost of performance or the overhead of a runtime. There was really no other language that had the expressiveness of C++ while allowing the developer to get down to the bare metal if they needed speed.
The existence and growing popularity of Rust changes that calculus, and I imagine that makes certain developers who might have a lot of investment in the C++ ecosystem defensive, causing them to overreact to any perceived slight in a way that other languages simply don't provoke.
Few things in this life are novel. Regardless, when I wrote ripgrep, I was focusing on writing new and better software. I perceived several problems with similar tools at the time and set out to do something better.
Imagine if people actually listened to whinging like your comment. I'm glad I never have.
Public domain. No "copyleft" license needed
Being written in a small, fast, "old and boring" language may be part of what makes SQLite apealing. Another (related) part may be the thoughtfulness and carefulness of its author, e.g., "time, attention and testing"
As suggested by the top comment, in effect the author's language choice, by itself, may be irrelevant regarding the issue of safety. If true, then even an "unsafe language" may not reduce the value of SQLite^1
djb's software is also public domain and written in an "unsafe language", mostly the same "old and boring" one as used to write SQLite. Like SQLite it is appealing to many people and is found in many places^2
1. But the thoughtlessness and carelessness of an author, no matter what language they choose, is still relevant to "safety" and may reduce the value of the software
This is obviously not analogous to Rust evangelism that targets projects written in C
The author claims the program is a clone of ack; ack is written in a "safe" language
Instead what I see _mostly_ is re-writes and proposed re-writes of existing software, often software that has no networking functions, and/or relatively small, easily audited software that IMHO poses little risk of memory-related bugs
This is concerning to me as an end-user who builds their software from source because the effects on compilation, e.g., resource requirements, interdependencies, speed, are significant