Word for a place filled with unpleasant people [closed]

Solution 1:

hotbed

1. An environment conducive to vigorous growth or development, especially of something undesirable: a hotbed of intrigue.

From AHD https://www.ahdictionary.com/word/search.html?q=hotbed

There’s a difference between hotbed of and hotbed for captured in this definition.

Solution 2:

cesspool seems like a good candidate:

1. a covered hole or container in the ground for collecting waste from a building, especially from the toilets
2. a place where dishonest or immoral people gather
   • a cesspool of corruption

Solution 3:

I suggest (from Lexico)

breeding ground
_NOUN

1.1 A place or situation that favours the development or occurrence of something.
The Web is indeed a modern-day breeding ground for unscrupulous forgers

It is often (but not always) used in a negative sense, and you can say

Many say that the industry is a breeding ground for narcissists.