While most liberal people turning in for the first time would likely think that both Ian and Mark are very racist people, that's because the people lack both an understanding of what race is and don't know Ian and Mark very well. Sure, they say stuff that people may consider racist on air. So does Puke and others. However, I doubt any of them are anything like so called racist. Anyway, acting like they are against Chinese certainly isn't as bad as their anti-christian stuff in the eyes of the vast majority of Americans. Ian and Mark also constantly make fun of southern people.
Let's face it, it's humor. Ian and Mark constantly make fun of various groups, but it's all in good fun (at least to the podcast listeners that are in on the jokes.) I don't think FTL would be as interesting if it wasn't so edgy and purposefully offense to almost the entire listening audience. FTL is the South Park of talk radio though the production value is nearly nothing compared to South Park and FTL is more political than South Park.
Many of us grow up on Married with Children, the Simpsons, Family Guy, Futurama, South Park, Mad TV and/or Saturday Night Live and so on. Many of us act that way in Keene from time to time. I only know of one person that is very bothered by it, though, and even he acts that way.