Why the "ese" suffix is added from a cultural/historic is etymology concentric. It is best to check reliable etymology dictionaries to trace the history of English word origin, including English prefixes or suffixes.
The correct term for "ese" is "suffix."
word-forming element, from Old French -eis (Modern French -ois, -ais), from Vulgar Latin, from Latin -ensem, -ensis "belonging to" or "originating in."
There are other suffixes here:
-ian (Italian, Norwegian)
-ean (Chilean, Korean)
-an (American, Mexican)
-ese (Chinese, Japanese)
-er (Icelander, New Zealander)
-ic (Icelandic, Greenlandic)
-ish (English, Irish)
-i (Iraqi, Pakistani)
It's possible you glean and confuse negative connotation for the suffix "ese" and misapply a historical, Latin or French "ese" [originating from Japan = Japanese, originating from China = Chinese; Vietnam = Vietnamese, etc., with Oxford Dictionary below on "ese" definition?
Definition of -ese suffix from the Oxford Advanced Learner's Dictionary
(in adjectives and nouns) of a country or city; a person who lives in a country or city; the language spoken there Chinese Viennese
(in nouns) (often disapproving) the style or language of journalese officialese
Separate a centuries old etymology on the origin of suffixes from peoples of today
using "ese" to denote something "disapproving," like many English speakers create their own slang using "ese" as if they are some kind of "otaku" in something (I live in Japan - 1970 to Present, but I am originally from the States.
"I speak ski ese" (which makes it sound like I not only ski, I eat, sleep, breathe every waking moment skiing. It's considered slang creating words like this which I just did. Meaning is disapproving in that it is way, way more than any normal person who skis would do. The connotation is, it's so much so that its become another language that other people can't speak (haha, like the image of an "otaku" in Japan.
The etymology of "ese" meaning "origin" is separate. Separate from a current phenomenon of English speakers in some areas attaching the "ese" to adjectives and nouns that have negative connotation.
Hope this helps. Like the Oxford dictionary does, treat as separate.