Diversity is a politically correct euphemism for a divided society. In particular, it refers to mass immigration creating a divided society, but may also refer to increased prominence of other minorities (such as sexual minorities) and reduced homogeneity in a society in general.
Increased "diversity" and a more divided society is often promoted by various minority groups, due to this being perceived as in the interest of their own group, even if this should be negative for society as a whole. Opponents are often smeared and persecuted in various ways, such as by labeling them as "racists" or as being mentally ill by using "-phobia" labels.
A high "diversity" and a highly divided society is often claimed to be something beneficial in itself, which is highly dubious. Language diversity causes a need for translating that is unnecessary if everyone speaks the same language, religious and ethnic diversity causes religious and ethnic conflicts, cultural diversity creates misunderstandings, "racism" against immigrants causes the need for tax-payed "anti-racist" organization and "anti-racist" educations, the different groups will create lobby groups lobbying for their own self-interests, and so on.
Research on ethnic heterogeneity has found that divided societies have numerous and severe problems.
In addition to these negative effects, a high "diversity" and a more divided society is often promoted while ignoring that that newly added groups may differ negatively from older groups on variables such as average measured IQ and crime, possibly causing negative developments for society as whole on average on such variables.
Those who support increased "diversity" and a more divided society at the same time often support affirmative action, in effect opposing "diversity" regarding the composition of different organizations by demanding that organizations should have the same composition, in addition to the many negative effects described in the affirmative action article.
Those who promote "diversity" and a divided society often also promote race mixing, which if universally practiced would actually eliminate the desired racial "diversity". In practice, race mixing does create more "diversity" by creating new mixed-race groups, but such and other effects of race mixing have many problems.