Because, in the embedded world, you better have a good fucking explanation of why you are using dynamically allocated memory.

Bring a formal proof that you won't go out of memory. Attach additional information on how you wrote an allocator that runs in constant time and does not risk taking it's sweet time to scan a huge area of memory. Sure, it's all O(n), but who cares if determining when you are going to hit the huge n case is equivalent to solving the halting problem.

Of course, at this point, the hassle simply means you don't use dynamic memory.

In my experience in the embedded world it is at least recognized that RAII should be used. It is fast becoming the exception not to use RAII and now that smart pointers are in the standard, the same goes for them.