Your not alone, I program in C/C++ in AmigaDE. I do not plan on switching to VP anytime soon. I am not ruling out VP, it is the native Amiga DE language. I just prefer C/C++.
If I create a routine in C (minus Intent/Elate/Amiga specific calls) -- ala my own, I can take those to other platforms or bring in routines I've already written (note: depends on licensing/agreements, if any were made).
You can convert routines from C to VP and VP to C (well not automatic). However, since I have not done any VP coding, there could be instances of one language having something the other doesn't.
I know myself and others have been working hard on making C/C++ tools, libraries, etc for coding in Amiga DE.
I'd suggest in general, look over the languages available on DE, then decide which is best suited for the application/tool you are creating. Also, consider if this application/tool will be taken to another platform where AmigaDE doesn't exist.