That's one of the most ridiculous, co-dependent contentions I've heard in a very long time.
If those family and friends don't like it, they should remove that person from their life. When children are involved the sober parent should keep the kids.
Besides, I have lived in CA and WA all my civilian years and I have not seen any evidence of the use of pot by a parent harming a child. I have seen dozens of case where alcohol harms a family/child. That's just MY experience...but one that most people on planet earth can attest to for their own.
And I can assure you that it is my experience that what I said is also true....and I am most definitely NOT co-dependent but thanks for throwing around the psycho-babble. Enjoy your smoke....