KGT says that using the non-language-user possessive suffixes (with the example of {joHwIj} instead of {joHwI'}) is considered insulting, as it implies the {joH} in question is a lesser kind of being. A similar principle might apply to the plural suffixes, though I don't think it's explicit anywhere. That is, {petaQmey} might be used as an additional layer of insult to imply that the p'tahks are lesser beings, without the brainpower necessary to use language like a person. It could also mean "p'tahks all over the place", but if the p'tahks are in one place, the insulting meaning might be intended.