I have been leaning more towards the mind my own business. The only reason I entertained the thought of intervening is , before my wife quit, she wanted me to talk to him. Now I have no vested interest other than the gripes i hear at my game and wanting to see a friend succeed.
My wife has told me the reason that they die is because the DM does not adjust the module to 2 "eccentric" personality players. One player is the kind of guy who hates feeling like he's on a railroad. So he goes off and does things that will not be obvious. He does not like to powergame, and makes characters that he has described as "useless".
The other guy is a powergamer who likes to test his powerful builds by seeking over the top challenges.
These two guys barely get along in real life, and thus never work well together unless you give them a thread that unites their two obsessions.
My wife described an inccident last night of the last TPK. They were walking across a field, there are tracks of a lvl 15 creature (they are 5). Instead of going to the town like they are suppose to. player 1 goes to hunt down the creature. Player two goes along to test his character out. The other two characters walked away but out of guilt went to help in the end. TPK.
Also, they tend to rarely have a full session, so often 2 or 3 people will be missing, but the DM never scales down the module.