This phrase is loaded with presumption. It implies those who are "socially excluded" are subjected to some proactive force, some conspiracy that should not be there, should be compensated for, or reversed. It has many similarities to the terms "Deprivation" and "Disadvantaged".
If "social exclusion" were narrowly applied, such as in the case of disabled people, then it might have weight, but the social services industry never miss a trick to have a remit broadened or creep a mission, so this label is also applied to people who are lazy, feckless, criminal and antisocial and is used, of course, as a ticket to gain Other Peoples' Money.
Judging by the present use of the term, a 40+ white male is 'socially excluded', but I think you will find that the Parasites could not bring themselves to use it in that case.
Maybe the best way is to just ask those parasitical self-loathing creatures infesting Social Services who is NOT socially excluded.