Some say such activism is counterproductive as it reinforces the negative stereotypes about apostates and feeds the JWs' persecution complex. I understand where they're coming from. Such criticisms are valid but I think they're merely the disadvantages of this type of activism. What about the advantages?
Memorial is a key meeting to target with activism because it's the meeting with the highest percentage of non-JWs present! So we can talk about the negative impact it has on JWs. What about the positive impact on non-JWs?
A large number of non-JWs would find the memorial of JWs to be strange. But for a non-JW sitting in a crowd of compliant JWs its easier for him to dismiss his own reservations about the matter. It's easier for him to tell himself that the problem is with him - that he just doesn't understand the truth of the matter as the JWs do. Having vocal activists present and brave enough to challenge the authenticity of the observance serves as a form of confirmation to all the non-JWs present who are thinking to themselves that this doesn't seem right.
Without the activists present some non-JWs be thinking: "It just doesn't seem right - but maybe it's just me. I mean, these JWs do seem to understand their bible pretty well..." But with vocal activists present, more non-JWs be thinking: "He's right, Jesus did say to eat my flesh and drink my blood. I know this doesn't look right. And clearly I'm not the only one who sees that." Some non-JWs also be thinking: "What drama! You don't see that at a weekly sunday mass, do you? What would motivate someone to do that? He seems knowledgeable of their beliefs. He must be a former member. This religion must have done a number on this guy for him to feel motivated to do something like that. I think I'm going to look up former JWs when I go home. The fact that ex-members are like that points to the fact that there must be hidden darker side to this religion."
See folks! Activism isn't all or only about reaching JWs. I dare say activism should be primarily about reaching non-JWs! Stunts like this reach non-JWs! It is far better to reach the non-JW public than attempt to reach JWs. It's like fighting Ebola. It's far better to work on vaccinating vulnerable populations than trying to find a cure when people already get it.
Reaching the public = vaccination against the JW mind virus = greatly stagnated JW growth = more JWs being exposed to TTATT at the door from non-apostates = more JWs doing serious research to prove the TTATT heard at the door wrong = more JWs waking up!