One major reason why orcas don't see humans as being potential prey is likely because orcas are just highly cultural animals and are usually very selective and conservative predators. Though orcas as a whole "species" prey on a large amount of different species, they belong to very different populations, and each of these populations has its own unique culture. Due to these cultural reasons, orcas are often unwilling to change from their pod's/community's diet. Culture in orcas does not only determines the different learned diets and hunting techniques amongst different orca populations, but it also determines their different communal social structures, vocalizations, traditions, social norms, play activities, and more amongst different orca populations.

The most comprehensive theory on why orcas do not desire to eat humans supported by marine biology can be summed up as follows. Orcas learn what to eat from their mothers. These dietary preferences are passed down generations (culturally transmitted) within an orca population. Specific diets form a major part of the cultures of each unique orca community/population. Culture seems to be very important to orcas, and thus orcas will rarely stray outside of the diet they are taught to eat by their podmates. In addition, even to mammal-eating orcas, humans likely simply do bear any resemblance to the various mammals that these orcas are familiar with. Thus, orcas do not recognize humans as potential prey.

However, another reason why wild orcas are not interested in harming humans may be due to them having theory of mind. Jared Towers, the lead author of a recent paper on the behaviour of wild orcas gifting/sharing prey and other objects with people, has also stated that orcas may have theory of mind in an article.

Basically, orcas having theory of mind would also mean that they could have the ability to detect and recognize our mental states. This also means that they may recognize that us humans also have our own different perspectives and that we also may also be another highly social and intelligent lifeform. Orcas as well as multiple other cetaceans do seem to view humans as fellow social beings that they could attempt to communicate with. Also, unlike other cetaceans, humans may represent a realm (dry land) which orcas do not have access to, so perhaps this could make them more curious.

Orcas do not really interact with many other species in this way, usually either ignoring, harassing, or killing other sea creatures. It seems that orcas see humans a bit differently, perhaps being more similar to themselves.

The food-sharing behaviours are considered exploratory behaviours by the researchers because orcas are observed usually pausing to see how humans respond to their actions, and thus the orcas are likely "testing" the humans. The behaviours of orcas offering food and other objects to humans are likely just extensions of well-documented cultural behaviours where orcas share food with each other, likely forming and strengthening bonds between each other. The researchers have thus labeled the behaviour as a form of "generalized altruism," where the orcas extend this behaviour across species towards humans as well.

Possible reasons for the orcas to engage in this behaviour are stated by the authors of the research paper:

"Offering items to humans could simultaneously include opportunities for killer whales to practice learned cultural behavior, explore or play and in so doing learn about, manipulate or develop relationships with us. Given the advanced cognitive abilities and social, cooperative nature of this species, we assume that any or all these explanations for, and outcomes of such behavior are possible. These cases suggest that societies of generalized reciprocity are prevalent in some populations of this species and indicate that as in humans, sharing is a cultural by-product used by killer whales outside of their own species to explore relationships within their respective environments."

As is also stated by Towers:

"There’s not many other wild creatures out there with enough intellect, resources or guts to test us like this which suggests some convergent evolution between our kinds and highlights that next level respect should be exercised in the ways we interact with them."

Perhaps another reason why various orcas seem to be more curious about us and are more willing to form some kind of relationship with us is not only because they may perceive us as being on a cognitive level of similar to themselves, but also because we come from a world (dry land) totally alien to them, while they have frequently seen other aquatic species, including other dolphins, for millions of years.

In an old documentary about the famous intentionally-stranding orcas at Punta Norte, Argentina, orcas appeared to befriend local park ranger Roberto Bubas. Dr. Jane Goodall states in the documentary that the orcas wanted Bubas in the water with them because they wanted to experience him and were curious about him as an individual. Bubas may also represent another world (dry land) that these orcas could not experience themselves.

Humans may represent a world that they cannot ever access. Thus, orcas could see forming a relationship with humans as being ultimately beneficial to themselves, as we may offer something that they cannot attain by themselves.

And indeed, there have been extensive historic relationships between humans and orcas, the most famous of which was Old Tom's pod forming a cooperative relationship with whalers in Eden, Australia. Both Aboriginal and western whalers cooperated with these orcas in Twofold Bay, New South Wales. The orcas would alert the whalers to the presence of baleen whales in the area by breaching or tailslapping near the cottages of the Davidson family. The orcas would also often assist in the hunt itself. After a whale was harpooned, some orcas would even grab the ropes with their teeth to assist the human whalers in hauling. It is possible this cooperative relationship was actually started by these orcas approaching and offering humans their food and the humans reciprocating many years ago, or vice versa.