I consider symbolic interposition to be one of those things. Linux users might not feel comfortable about the fact that glibc currently makes it so easy to intercept system calls to Linux Kernel's RNG, that your upstream dependencies might actually compromise your key generator unintentionally.
Don't you think that's worth discussing? We could also talk about the concerns surrounding Layered Service Providers, which is another great example of userspace libraries misrepresenting APIs that are generally believed to be talking to the operating system.
Users get to control how programs execute. They can interpose symbols. They can disassemble programs. They can run programs under a debugger. They can modify the kernel. They can run programs in a VM. A program can't detect this intermediation; nor does it have any right to do so. A program has no business breaking random OS visibility and control features. We generally call the ones that try malware.
Bypassing libc when making system calls doesn't give a program any insurance against environmental changes. It just inconveniences users while providing no "safety" guarantees. If you want full control over a program's execution environment, ship an appliance.