Kevin, 5 years ago I had the same problem with my son and better half. Sauce over everything - couldnt bare to see a hint even of pink. I've gently worked them towards it. By stealth :D
I started with beef stews etc. You know the point where you've browned off the cubes and they are still tender, but then simmer for couple more hours to get it soft again? I'd get all the sauce(*not tomato ketchup!) for the stew, veg, beans etc combined seasoned, keep it on a simmer, ready to go. Then brown the meat.. nice n brown & caramelised on the outer, juicy and pink on the insdes.Straight into the sauce - serve immediately. The sauce covers the pinkness. Easy cheat to help the palate and change attitudes.
Chinese cooking helped too, where you only brown the meat then pull outta the wok/pan. It's barely cooked. But so tasty. And they can look at it all they want - it's brown, and so soft.
I used bbq lamb chops too. Long marinade, sear couple of minutes on the gas grill, out to rest in warm place tented in foil. Juices relax back in. Then they could smear all they like with bbq sauce. It's such a lovely brown colour - camoflage!
My MIL would go out, order a rib steak - then insist it be well done. Then complain it was tough as old boots. Poor dear had false teeth so that made it worse. So much wasted steak.... But she was old country girl who grew up without fridges, and the meat pretty much had to be cremated after storing in the meat locker for it to be considered safe.
You can lead a horse to water but you can't make it drink. Some will change, some won't. Frustrating I know. Gently does it. Good luck!