Purpose is just another side of cause. This is what I take as a premise. One might change "cause" by "reason" sometimes, both are related.
Every non-randomistic process has some end after which this process can stop. This end may be unreachable in any finite time, but taking recursively enumerable function, it is. Otherwise it is randomistic process. This end is what I call purpose.
Even two electrons, when they move away (effect) from each other, do it because of electromagnetic force (causal part). At the same time they do it in order to be as distant from each other as possible (purposal part). Now, we may assume that every effect is connected to some purpose. There is another, different from currect, state of things that seems to be more appropriate/better/more suitable to the laws of physics/etc.
So, when we may examine philosophers. Since philosopher also had some effects on our world and society, or in plain words, they just affected our world and society, then they had some purpose. This is also true for value philosophies. E.g. Aristotle and Kant developed their moral philosophies in order to change state of things. Change governance, law, social attitudes, etc. If they did not want to change things, then they would not have purpose. And then there would be no their moral philosophies. Also, their philosophies contain such notions as telos and maxim which are linked with the notion of purpose.
Now we can move to consequentialism part. At first, there are at least two completely unequal forms of consequentialism. One says consequences of actions made are the basis for their judgement. Now we can look at one example of this:
Suppose there are two persons who want to kill innocent people. The first one was successful in doing that and therefore commited murder. Another one, was unlucky and could not kill innocent person he chose as a victim. So, since actions of the first one resulted in worse consequences, he deserves more severe punishment.
Another form of consequentialism says, that one should strive for the best consequences. Therefore, it involves the notion of intention. According to it both people who intended to kill people are equally wrong, since they wanted the samely bad consequences.
So, assuming second definition of consequentialism, whatever consequences are counted as bad or good, is everyone a consequentialist?