The tag encourages users to delete the article rather than fix problems. That is...

tptacek · on Aug 14, 2009

That's precisely what the tag doesn't do. If you want to encourage people to delete the article, you put it up for AfD.

Goladus · on Aug 15, 2009

Then why not remove the warning saying "this article is likely to be merged or deleted"?

"Does not meet notability guidelines, please help fix" is not the same as "Does not meet notability guidelines, help fix or this article gets deleted." The latter frames the issue as content not permitted, the former frames the issue as content yet to come. The difference is significant.