This is obviously not true. Language matters. Are you as productive in BrainFuck as in C++? I don't think so. C/C++ isn't the end of all progress in language design. Modern languages eliminate or vastly reduce whole classes of concerns like memory management, wild pointers, null pointers, incomprehensible template errors, etc. Some of these problems can be patched up for perhaps 30% by a post hoc static analysis, but the effectiveness of that is much less than a language that has been designed to make these errors impossible by construction. Modern languages also make lots of stuff easier through a good standard library, language features like closures & type inference, a REPL, a good IDE (the feasibility of which is also a function of language design), etc.
Sure, they don't solve the problem of magically and instantly conjuring up the program you want; nobody is claiming that. All these little things add up nevertheless.
I was responding to this: "Changing the language doesn't bring anything." and this: "You cannot reduce risk, you can only replace it with another", not to the Wikipedia entry. The Wikipedia entry is very reasonable, and does not make the same outrageous claims.
"Changing the language doesn't bring anything." -> This is because the largest contributor to code quality is the coder. C is already a "safe" language as opposed to assembly or even writing the opcodes yourself.
"You cannot reduce risk, you can only replace it with another" -> I just ask you to think about it, try to have an open mind about what I may imply. I'm sorry for this mysterious answer but this is typically a topic over which we could talk past each other. The first time I was told you I had the same reaction until I had the epiphany about what it really means.
Your first paragraph is repeating what you already said, which is exactly what I responded to. To summarize it again: that C is high level or safe compared to assembler does not mean that other languages aren't significantly higher level or safer than C.
Your second paragraph is on the border of being condescending without any actual argumentation.
Sure, they don't solve the problem of magically and instantly conjuring up the program you want; nobody is claiming that. All these little things add up nevertheless.