I've never thought about it, but I agree with you.  Especially with respect to obituaries which go into the newspaper and for which you pay by the word/line.  I certainly wouldn't want to PAY to list estranged people I don't care about.  

It may be morbid, but it is something I have thought about. My affairs are set up such that my (adult) sons will be in charge. If DH is alive when I die, they will list the SDs out of respect for him. If DH passes before me, they will not be listed.

I am in charge if DH dies before me, and I will list my kids (his skids). If I am deceased before DH, I doubt his kids will even list me.

I told my DH I do NOT want a funeral.  No service, no obituary, no burial, no tombstone...zip!  But he pointed out (quite rightly) that the funeral isn't for me.  It's for those left behind.  So if it makes people feel better to gather, or (in the example you mentioned) to see their name in a list of people who cared about me (whether they did or not), or even it it would make they happier to be left OUT of a list that society thinks they should be on...what do I care :)  I'll be dead!  Leaving a little peace behind, when it costs me nothing, seems like a last act that speaks to my character, not theirs.  

I don't want SS and his wife listed on my obituary.  If dh goes before me, as of right now SS would not be mentioned.  I probably wouldn't even want them at either of our funerals.  They'd probably be too busy celebrating to attend mine so hopefully my bios wouldn't have to worry about keeping them out. 

I'll be dead so I'm not certain I will care about anything in my obituary (if there even is an obituary).

I understand we'll be dead when these things happen, but people honoring wishes is something I think is important. Why make it sound like they were part of your family when that isn't really how it is?