This was an interesting article.
It sounds like some are saying that slower runners take away from the 'prestige' of the run while others think the marathon wouldn't be as popular as it is today without slower runners. My take on it is that I believe the way to resolve some of the problems is to stick with the noted cut off times for each marathon. If it is a 6 hour cutoff, then don't officially count a finish after that. I have had 10k races that only counted the top 100 finishers and not the other 9000. The other train of thought of having 'proof ' of your running time is another good way to keep 'plodders' at a minimum. When I signed up for the Disney Half Marathon, I was required to send proof of time. Of course there may be exceptions, but these are controlled by the race director.
Having said all of that, I think some of the complainers of the plodders were pricks. Since when is running a +4 hour time tarnished or diminished by someone running a +6 hour time? You should really check yourself! What do you think the 'elite' runners think of your SLOW time when they finished in just under 2 1/2 hours? Do you think they are going, " man, all these slow +3 hour runners are REALLY bringing down the prestige of the marathon". Granted, stopping to eat lunch during a marathon is a bit overboard and for all practical purposes, I think you should be able to run SOME of the race to actually be a part of the marathon (walking 26.2 miles to me is not the same) but the story of the marathon is the sheer effort, time and sweat put into doing it. If you look back at the most memorable moments of a marathon, I think human achievements , not fast records , are what dominate the storylines of the paper. There are only a handful of people who will ever be able to truly WIN a marathon but there are millions who can show great accomplishments at the race.
So in a nutshell, I think plodders have a place, but each race should do what they feel appropriate in enforcing cutoff times.