I agree that counsellors can be very hit or miss and also think the MLCer will hear only what they want to hear.
In my case, H did see a counsellor who basically told him that "sometimes feelings do change, there's not always a reason why....so when you move out make sure to get a house with enough bedrooms for the kids and for gods sake get a lawyer" well that's what H told me anyway, who knows what he told the counsellor or what the counsellor actually said. It's all so filtered and skewed by perspective.
I saw a fantastic counsellor for myself for almost two years, who believed in "life crises" that arose out of " unresolved issues". She carefully avoided talking of a mid life crisis but in any event her focus was on me and making me think about the future I wanted and how to cope with what had happened and also helped with some issues with my children. I thought she was great, a life saver in fact. But perhaps that's MY perspective!!
We did see a marriage counsellor a few times. H agreed to go saying "it won't change anything for me but it might help me find the words to tell you why I need to leave" well, he never found the words except to accuse me of being too rigid and controlling, our relationship for being too insular, my family were all socially inept, and he "just can't go back to that relationship". The counsellor was not really prepared and admitted to me later that all Hs reasons were insubstantial and then jokingly mentioned MLC. At least he put me on the right path there and that's when started searching and came across this forum.
I asked the counsellor about MLC a little later. He agreed it was real enough and all I could do was leave H to sort through his stuff. he also agreed that MLC destroyed families and marriages but there was little he could do unless H chose to seek help. He was very good and tried to follow up with H but was just got lied to to eg rang H workplace to be left on hold for 30 mins then was told H was on leave when that was not true. I suspect OW (his PA) had a hand in that deception. I can picture the two of them conspiring together to get rid of the nasty counsellor on the phone.
I have an expectation that counselling would be part of any reconciliation attempt ... I would steer H away from his original counsellor and head him towards the counsellors I have found to be more in tune with the MLC idea and also pro marriage ... But perhaps I am just incredibly naive.