I am starting to hear this more often now.

Someone says, "I can't stand such and such. S/he has issues."

I respond, "Then distance yourself from him or her."

The person replies, "Oh, but s/he helps me out when I need him/ her."

I want to say:

"You can't have it both ways:
If you can't stand someone, and is always going to complain about that person to me, then be prepared to let that person go and forego the help.

If you insist on keeping that person around in your life to help you, then you are going to have to become more tolerant of that person and stop complaining about him/ her to me all the time.

But you can't have it both ways."

Does that sound too harsh? If so, how would you reword this?