Is there a term for when people group 2 unrelated things they dislike into one entity?
Solution 1:
Sounds like someone is stereotyping another person.
Macmillan:
stereotype VERB
1 to believe that someone has a particular character only because this is what many people believe someone of their particular class, nationality, etc. must be like, and not because you know anything about their personality
stereotype someone as something: Feminists are sometimes stereotyped as aggressive and unattractive.