Well VB & C# aren't portable. But if you want really small & fast programs, why not go a step further and program in assembly?
I'm not saying there's no use for C. Sometimes you have to use C (or assembly), but since C++ gives you so many more tools to write and manage your code, why wouldn't you take advantage of those tools when the option is available to you? For example, in C you have to write way too much code to check if malloc() failed, free memory before returning, checking errno...