What makes people think lifetime bans will work? They hang people in Malaysia for using drugs, but people still do it. In the U.S., hundreds of thousands of people have been put in jail, thousands for life, for using and selling drugs, and people just keep doing it. Authorities are always increasing the severity of punishment for offenses on the promise it will reduce occurrence and they'll keep on doing it forever--if it worked, you'd think there would come a point when they didn't have to do it anymore, but there never does. Makes me think people who propose lifetime bans are more interested in revenge than deterrence.
There are hundreds and hundreds of PEDs. The cost of testing for them all is too great, and if you don't test for them all, then it seems likely that people will have an incentive to use the PEDs they think are not being targeted. If you test for them all, then in view of the cost, you can't test frequently enough to ensure detection, so people have an incentive to try to use during the window of opportunity. IMO, as long as there is an incentive for using PEDS, athletes will use them, and as long as people crave victory and whatever rewards go with it, there will always be such incentives.
I think this is a great sport, and I think that even though I think everyone's doping. I don't think I'd like it that much more if no one were doping, and I know I like it less with all the scandal. For selfish reasons, I'm more interested in eliminating scandal than eliminating doping. And lifetime bans escalate the scandal. It that's what you want, well, to each his own, but it seems like a self-defeating and futile approach to me.