Non-violent protest are counter to their agenda. MalcomX had a similar disdain for those type of leaders and accused them of being grifters.

Ironically MLK died broke (1968):

https://www.gobankingrates.com/net-worth/celebrities/martin-luther-king-jr-net-worth/

And MalcomX was worth 150k (in 1965):

https://www.celebritynetworth.com/richest-celebrities/authors/malcolm-x-net-worth/