There are at least a couple reasons non-minoritized users here "don't see the racism here". One is technical, sometimes: not all replies are visible for all users, etc. 

The other is not: sometimes racisms are subtle, polite, dog-whistle-y, leaning hard on plausible deniability, etc. 

Anyway if minoritized users here say they see/are subjected to racism here, it's helpful to just believe that and keep one's ears and eyes open. *Whether* it's happening isn't a useful point of entry.