Killer whales, or orcas, are the largest members of the dolphin family, and are the apex predators (they don't have any predators). They are known to live in all oceans and almost all the seas.
Life in rocky seashores is difficult and complex due to a number of factors. There are extreme changes in temperature, salinity, moisture and wave action. For example, during low tide, there is less water, moisture levels are low and animals would be exposed to more sunlight and thus hot, drying conditions. During rainfall, the salinity levels would be low and it would be high during high tides. Apart from these physical factors, there is strong competition for space and food. In addition, animals also have to protect themselves from wave action by attachment, which may not work for a mobile predator like an orca.
Due to these significant challenges, orca rarely spend significant time in rocky seashores.
Hope this helps.