In the phrase "He criticized the revolution and its ______" I originally wrote "perpetrators," but that casts a negative connotation on the revolution, as if it is a crime. I don't want to use "revolutionaries" as to avoid the sentence sounding too repetitive, so what is a more neutral word I can use for the revolutionaries in question?
From a comment under the question, I see that adherents is what was being looked for. However, I think that followers is more natural in this context:
[Merriam-Webster, from the verb follow]
2 a : to engage in as a calling or way of life : PURSUE
// wheat-growing is generally followed here
2 b : to walk or proceed along
// follow a path
3 a : to be or act in accordance with
// follow directions
3 b : to accept as authority : OBEY
// followed his conscience
Using it in the example sentence:
He criticized the revolution and its followers.
The criticism of a revolution is often of the principles involved and the followers of those principles. These things can exist before, during, and after the revolutionary event itself.
Google Books Ngram Viewer indicates that and its followers is more common than and its adherents:
You can use a straight up synonym for revolutionary such as insurgent:
For contemporary national revolutions, the capture and control of territory has virtually become a "territorial imperative." ... "Mobile war" is required when the insurgent is unable to establish a base in the cities and must continually move to avoid capture by government troops. —The Insurgent State: Territorial Bases of Revolution
Another option would be to use a generic word such as supporter or leader which might have a more relevant nuance.
If you mean its leaders, another word that would work here is "instigators," which has a negative connotation that goes with the criticism indicated in your sentence but is not as heavy-handed as, and better fitting than, "perpetrators."
If you don't mean the leaders, "participants" might be a better word than "followers;" as indicated in a comment above, it would seem more natural to say you are a follower of a revolution's principles than to say (about a revolutionary) you are a follower of the revolution itself, as in your sentence.