Differences in Missionaries Between Denominations

I've searched through most other missionary threads and have not found a decent answer to this. I am familiar with LDS/Jehovah's Witness' definitions of missionaries, usually as proselytizing missionaries going door to door attempting to convert people from one religion to theirs. While I was perusing the other threads about missionaries, specifically the one here: https://christianity.stackexchange.com/questions/25252/which-churches-today-send-the-most-missionaries I came across an interesting point that someone made. J Dawg's answer on the thread said something to the effect of "Mormon and Jehovah's Witness missionaries aren't really missionaries as they don't do *so and so*" So my question is, why is there a discrepancy in what people think missionaries should be? I feel like the bible outlines this pretty clearly in Matthew: Matthew 28:19-20 (KJV) > 19 Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: > 20 Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world. Amen. As per Kris's comment, here is the definition of missionary I am looking at: >A missionary is a member of a religious group that is sent into an area in order to promote its faith or provide services to people, such as education, literacy, social justice, health care, and economic development. Under the definition of missionary provided, why do many denominations not consider LDS/JW "missionaries" to be missionaries?