Alternative: Studying in the United States to get a Ph.D. is only a part of his resume, so why is it the object of being attacked by peopleare people attacking just that? Alternative: Studying in the United States to get a Ph.D. is only a part of his resume, so why are people attacking just that?

Can't you be psychologically sunnymore cheerful? Can't you be more cheerful?

I love how you wrote "psychologically sunny" but it's not a phrase we use in native English. Maybe I'll try making it one by incorporating it into my own way of speaking and writing.

Do people whoIs studying abroad necessarily have a bad virtue? Is studying abroad necessarily a bad virtue?

"Virtue" is an abstract concept so we don't really need the article "a" before it in this sentence. We also refer to behavior when assigning virtue. For example, people can be virtuous but their good attributes can be a virtue.

CTheir characters must be poor? Their character must be poor?

"Character" is an abstract concept so we don't necessarily make it plural when we refer to it.

There is not necessaryily a connection between them, but the mentality of some people! There is not necessarily a connection between them, but the mentality of some people!