Simplesearch returns _module pages

Is there a way to prevent simplesearch from searching or at least displaying non-routable _pagemodule in the results?

Use taxonomy to ensure only pages you want are searched.

That's the only solution? :/

Yes, this is a 'simplesearch' after all. I do have some plans to build a more sophisticated search plugin that uses an index and has much more sophisticated indexing capabilities, but this is some time off.