I'm using the standard plain style for my bibliography. My document is written in Dutch, so I'm using the babel package, but the and separator before the last author isn't translated to the Dutch alternative en.
\documentclass{article}
\usepackage[dutch]{babel}
\begin{document}
\nocite{*}
\bibliographystyle{plain}
\bibliography{references}
\end{document}
After reading this answer, I know how to create a custom style myplain, where and is changed to en, but I was wondering whether it is truly necessary to create a new style for this.
Aren't babel and some other trick sufficient? If not, does one have to create a new style for every language (e.g. in French, and is et)?

andas a literal hard-coded. – Joseph Wright Apr 23 '16 at 18:07\harvardand– Apr 23 '16 at 18:27deplain.bstwhich usesundhttp://comedy.dante.de/~herbert/BibTeX/. It is easy to modify it for any other language – Apr 23 '16 at 19:20biblatex. – Bernard Apr 23 '16 at 19:26