"ese" suffix insulting/racist?

[Billionbridges.com]

In a rather hysterical article written in Chinese I came across
recently a Taiwanese person rants that the epithets in English
denoting nationality which use the "ese" suffix are insulting
and racist (where those which do not, such as "American" or
"German" etc., are not). The author claims that "ese" was
traditionally used by the English in adjectives describing unimportant,
weak, strange or sickly things or people(s). He further relates
personal anecdotes in which the term "Chinese" has been used
by Americans in scorn. In his estimation "Chinese" is as insulting
to, erm, Chinese as "nigger" is to African-Americans.

Hypersensitive and misguided? Clearly. An ignorant crackpot? Well,
the author has decided that in future when English-speakers ask
where he's from he will answer the "Central Kingdom of Sinai." He
is a Sinaian, he says.

Nevertheless, leaving Egypt and the politics of the Taiwan Strait aside,
I wonder where this author's conception that the "ese" suffix is insulting
came from? Or is this completely baseless and/or irredeemably idiolectic?

The link, for the Chinese-enabled:
http://teacher.cyivs.cy.edu.tw/~hchung/despisechinese.htm

Best,
Don