Why college people are so sophisticated?

Sophisticated ? Not here in the US .

Many college students aren't sophisticated, but those who are have become that way through life experiences and maturing beyond the level of high and grammar school students.

If there is any sort of "sophistication," it is because on certain academic levels, there is higher rigor.

Rigorous standards are used to ensure that quality research and content is produced.

There is quite a difference, however, between undergraduate "rigor" and graduate rigor.