Excellent idea for a thread.
Why do you consider this "kindness," to take one example, as a moral flaw? Your viewpoint is obviously anthropic. The orcs that we meet are the 'survivors' of a very cruel winnowing process. For all we know, the parents eat the young that they can catch. In this environment, altruism is suicide. Simply giving over a crust of bread or dried meat - regardless the source - could lead one to soon be dead, as the favor would most likely not be returned, be considered a sign of not being 'rightminded,' and so warrant penalty.
I'd like to think that we humans could easily become orcish via George Orwell's 1984, explored somewhat
here.
I like to think further on this, and will need to do some research. Are we agreed that orcs reproduce sexually? If so, and if we're dealing with the 'selfish genes,' then it would make sense for certain behaviours to be exhibited; unless, that is, prowess on the battle field did not lead to increased number of children. On the other hand, if there's some type of - let's just say - gene that makes orcs particularly covetous, then maybe those in charge make use of this for their own ends.