What it suggests is a lack of empathy, which extends to your assuming that other people are also incapable of empathy. Sorry, I'm also not sure how to word that more politely.
Imagine, for a moment, that other people are honest in their assertion that they are offended (for example that women find some common, everyday behavior offensive and sexist).
Imagine, for a moment that other people are capable of feeling empathy for those people (for example, that they have learned, through empathy, to notice the same sexist behavior and find it offensive, even though they are not women).
Then you might realize that they are not 'spending time and effort to find offensiveness', but just capable of empathy. Sorry if that seems outlandish, but.. it's the truth, sorry.