This is gonna be a long critique, I'll try to keep it concise.
> C-like C++ is good start, if code doesn’t require more complexity don’t add unnecessary C++ complexities.
C is almost obsolete nowadays. Not to mention that C++ is effectively a strict superset of C (nearly 99% of the C standard is in C++) and the few features that aren't are included as compiler extensions (VLA, restrict keyword, nested functions). There are a handful of C features that aren't in C++, and for very good reason (most of them suck).
When was the last time you ran into a C library that a pure C++ compiler couldn't compile? Only if someone decided to spam the new keyword all over the codebase (or something similar).
> In general case code should be readable to anyone who is familiar with C language.
Most C++ already is? Even very template heavy C++.
> Don’t do this, the end of “design rationale” in Orthodox C++ should be immedately after “Quite simple, and it is usable. EOF”.
A lot of the methods in that document are necessary to make C++ shine, especially template metaprogramming.
> Don’t use exceptions.
Optional but irrelevant.
> Don’t use RTTI.
.. Why? Reimplementing RTTI in C will give you almost the same overhead.
> Don’t use C++ runtime wrapper for C runtime includes (, , etc.), use C runtime instead (, , etc.)
.. Why? Those wrappers all include the "raw C runtime" under the hood (literally they do #include . Near 0 compiletime overhead?
> Don’t use stream (, , etc.), use printf style functions instead.
This is a design decision.
> Don’t use metaprogramming excessively for academic masturbation. Use it in moderation, only where necessary, and where it reduces code complexity.
There are many programs that are _impossible_ to write in a finite time without metaprogramming. How will you (with zero runtime overhead) dispatch a function with a variable arity of random types to a handler that requires exactly that type of function? Arbitrarily? In C++ it's possible, in C it isn't.