Answer:
Vile and disreputable.
Explanation:
The words 'vile' and 'disreputable' are the two synonyms for the word 'sordid'. No, it is not appropriate to describe large groups of people because it is condescending and insulting to describe large groups of people with such words.
For example, if someone says that the Asian community living downtown are sordid people, it means that they are vile and nasty. That is not an appropriate word to address a group of people. It is completely wrong.