I've never used C++, and I'm just a casual programmer, so I can't say too much about the difficulty curve. What I think most people are griping about is using OO code when it's not needed. C++ programmers really want to use OO design for everything when a simpler C program will do it just as well.
That's a coder dicision. Good programmers know to use a language that fits the task. I really don't know what happens when you try to mix C and C++ together. I presume that's a bad thing to do?
All I know is, when I complile a C program with a C++ compiler, the program turns out huge. I mean, just for fun I wrote Hello World in MSVC with default values, and it compiled to over 250K. WTF? Or is that just because it's Microsoft?