To sum up the discussion so far: wrongly or rightly, many people feel upset when their goods, forge points, etc. are stolen. Why do they feel this way? I can only surmise. Perhaps they are dismayed that people would choose to hurt the chances of others simply to move up faster in relatively worthless points. After all, everyone is presented with four choices in dealing with 'neighbors,' only one of which harms the neighbors. Plunderers respond that they are following the rules and that players should not complain, but rather take various anti-plunder measures.
Sure, plundering is within the rules and is encouraged by various rewards, but why is this the case? Perhaps, Inno has determined that a large proportion of those willing to buy diamonds are people who wish to reside in a position of power vis-a-vis other players. (We see, for example, how plunderers laugh or deride those who complain or who do not take anti-plunder measures.) If it was determined that even more people would be willing to buy diamonds in order to destroy the military capacity of their plunderers, that, too, would be within the rules, provided that it was not too costly to implement.
So let's examine why the 'victims' might not undertake anti-plunder measures. What about beefing up their defenses? In the early ages, if they themselves do not attack others, they may not realize that they have the ability to alter their defenses. Later on, they may feel---wrongly, I might add---that at least they can deny the plunderers 'tower points.' And they may conclude, given the game's "attackers' bias," that any reasonably-'priced' defense will be easily overcome.
But what about collecting 'on time?" Surely this is easy to put in practice. Not necessarily. Some may have schedules that are set by outside events or do not permit an assured collection other than on a 24-hour cycle. What's wrong with that? Well, on an 8-hour, 4-hour, 8-hour cycle, one can produce 25 goods per day in a dedicated factory. A 24-hour cycle cuts production by 20%; so it may be more prudent, if one has many factories and few plunderers, to take one's chances and aim for maximum production.
Perhaps the greatest reason for not undertaking anti-plunder measures has to do with world view. People do not like to prepare to face what should be rare catastrophes. People live in a flood plain and are upset when their homes are inundated and the insurance they have is insufficient. Or they live in an earthquake zone, but have no plan for 'quake survival.
Similarly, some do not wish to countenance the existence of those who would steal from others just to move ahead faster. By taking anti-plunder measures, they are, in a sense, justifying the plunderers, actualizing them. Just as curtailment of our liberties, even as it makes 'terror incidents' harder to achieve, tells terrorists that they've been effective, that they've been making progress toward their goals.
It seems that plunderers have a legalistic Weltanschauing: what is within the rules is perfectly okay. The victims, however, believe that not all that is legal is ethical. For instance, a world-class swimmer, upon encountering a drowning person, has no legal obligation to attempt a rescue, but many would say that it's unethical not to make such an attempt. The problem is that neither side in this discussion is completely right. How do we approach a modus vivendi in which plunderers feel their rights are upheld, while victims can be assured that their codes of ethics are not being torn to shreds?