I second this based on hard personal experience. You end up with platform-specific features, behavior and bugs, compounded across multiple pieces in the stack.

I second this based on hard personal experience. You end up with platform-specific features, behavior and bugs, compounded across multiple pieces in the stack. You also end up with conflicting design decisions. In my case, I wanted to use Apache & Python, but the recommendation is for a threading Apache on Windows, but forking on Linux (allowing e.g. mod_python). To be cross-platform, I ended up going pure python webserver at the cost of performance and then had to deal with divergent cpython threading behavior, as well as postgres win32-specific issues.