Not necessarily.

Main Entry: 1rant
Pronunciation: \ˈrant\
Function: verb
Etymology: obsolete Dutch ranten, randen
Date: 1601
intransitive verb 1 : to talk in a noisy, excited, or declamatory manner
2 : to scold vehemently
transitive verb : to utter in a bombastic declamatory fashion


It's use under the first provision would not necessarily be complaining.