The term reactionary means one who reacts against change, trying to reestablish the previous status quo. Reactionaries are seen as a conservative social force.
But what is the term for one who always reacts against the current status quo, no matter what it is?
Many different kinds of people may react against the current status quo but most are doing so to achieve specific goals that are important to them.
But some people will just react against the status quo no matter what it is, because "hey, I'm a rebel." If their apparent goals were achieved they would simply react against the new status quo.
Children do something similar, they test boundaries by reacting against their parents - rebelling is an end in itself and not necessarily due to a deep seated rejection of whatever it is.
I'm looking for a term that captures the knee-jerk nature of this reaction, that has the same negative connotations that reactionary has for many people, i.e. rebel/restore are practically algorithmic rather than intellectually driven.