Keywords tag is no longer useful for SEO

[aw73]

For several years now, the keywords tag is no longer used by search engines to index pages. Worse, some tests even show that this can be a penalty...

• Google - 2009
• Yahoo - 2009
• Bing - 2014

To avoid confusion, it would be nice if this field disappears MarkupSEO which is otherwise very good!

At least, if the field is not filled then the meta-tag is not generated ...

Thanks in advance