Why can't we use 什么的 ("and so on") with lists of people, and what can we use instead?

Question

My Chinese text book says this about using 什么的 ("and so on"):

I transcribe and translate this below (ignoring the first line; it's an example of using 什么的 continuing from the previous page):

注意：”什么的“只能用于物，不能用于人。例如，不能说：“我们班有韩国人，美国人，日本人什么的。”
Attention: "什么的" can only be used with things, not with people. For example, we cannot say "our class has Korean people, American people, Japanese people, and so on."
_{Zhùyì: ”Shénme de“ zhǐnéng yòng yú wù, bùnéng yòng yú rén. Lìrú, bùnéng shuō: “Wǒmen bān yǒu Hánguórén, Měiguórén, Rìběnrén shénme de.”}

Question: Why can't we use 什么的 with lists of people, and what can we use instead?

The book doesn't discuss why we can't say this, only that we can't. I guess it's because it's impolite to say this, but I'm just guessing.

I also don't know what we can use as an alternative (e.g. 等等 instead of 什么的), since whatever reason we should not use 什么的 might also apply to the alternative.

Answer 1

It can't be used for people because 什么的 means "things like"

写写信、打打球、洗洗衣服什么的 = "Things like writing letter, playing basketball, washing clothes"

Also;

To list specific individuals, we can use '等人'

Example: 陈博士，李教授，王法官等人 (Dr. Chen, Professor Li, Judge Wang and others like them)

~

To list different kinds of people or things, we can use '之類'

Example:

'医生，律师 和警察之類 ' (people like doctor, lawyer and police)

'足球，篮球 和网球之類' (things like football, basketball and tennis)

~

'and so on' = "等等"

Example:

'足球，篮球, 网球等等' (football, basketball, tennis and so on)

'医生，律师, 警察等等' (doctor, lawyer, police and so on)

~

To list different kinds of dishonorable people, we can use '之流'

Example: "小偷, 騙子和走私客之流" (the like of thief, con man and smuggler)

Answer 2

I guess it's because it's impolite to say this, but I'm just guessing.

What you guessed is right. More precisely, when 什么的 is used for listing it has negative connotations. Such as the sentence you showed,

课余时间写写信、打打球、洗洗衣服什么的。

During spare time (I only) write letters, play balls, wash clothes, etc.

[connotation] I don't have much time to do those interesting things.

That means, according to the context, if it matches your intent you can also use it with people.

As an alternative 等等 is fine, basically it's a neutral word, doesn't have any negative or positive connotations.