Leif and Bernard, I make exceptions for my living relatives whose DNA test information I want to display. (Of course, they have to join WT, but they rarely make any contributions other than to their own profiles.)
One reason I suspect that, as I said above, some newcomers add their entire living families is that there seems to be a huge difference (about 3.8 million) between the current number of WT profiles and the apparent number of WT numbers (the eight-digit number we can all find, for example, at the top of our suggestions lists) issued to date. The only reason I know of for deletions of large numbers of profiles from WT is that when a member quits, all the member's living profiles without any other profile manager are deleted.