Anne --
Mainly I tackle the bio by adding a timeline on the "main" person I've started to research, but I also end up adding profiles for family members from census listings, etc. So, if I took the time to write bios for every single family member, the family who lives in my house would be starving in dirty clothing. ;-)
So, yes, on SOME of the profiles, I'm happy to write the bios, and I enjoy learning the stories of each of these people. I just can't do ALL of them. :) As a matter of fact, the profiles of my direct-line family members have suffered because I habitually fall down the rabbit holes of other families.
Oh, and I also have a "bad" habit of checking the surname lists when I'm working on a new family, and then there are all those duplicates that need to be merged and the bio cleanups that nobody but me ever does. (Yes, I know there are others who clean up, too, but apparently I never propose merges on their profiles. :-( )
And now, at the risk of sounding a little self-righteous (I'm not; I swear) ... I don't think I mind asking for a little help with the bios!! ha!! :)
Thanks for listening to me prattle through this rationalization!