On real world where code portability actually matters, many do program against ISO C++, and have to deal with workarounds for lack of compliance.
Not doing so means ending up with situations like the Linux kernel, Windows or console games, which might be ok, when code portability doesn't matter to start with.
Not doing so means ending up with situations like the Linux kernel, Windows or console games, which might be ok, when code portability doesn't matter to start with.