There's a limit to the "meanness" one can stomach, however, without some aspect, such as mental health, going awry. In short bursts it may be useful, but in the long run, meanness is not sustainable.
It’s not that you should deal with mean people regularly, but if a mean person tells you a useful piece of information you shouldn’t dismiss it just because they were mean. After that you’re free to avoid interacting with them in the future (to the extent possible — if you can’t avoid them then it’s a moot point anyway and you should still seek to get as much from them as possible)
