Okay, maybe stop pretending that a GPM victory in the Giro or the Vuelta is anywhere near a GPM victory in the Tour.
The Tour's GPM had been counterbalanced less to prevent that kind of winner than the Giro or Vuelta, precisely because of that fact, because the higher prestige meant it was harder to win in the Virenque method without being an elite climber already. Charteau was just the first to do so, and that was largely the product of Prudhomme's poor course design, because that points method had never produced a similarly "undeserving" KOM before. Double points for final summit is absolutely fine, it doesn't have to be an MTF (which it is now), and the bias toward HCs was better then as well. However, stages like 2009 Tarbes and 2010 Pau, combined with that being the era of no bonus seconds so the GC guys left almost all the mountain stages to the break, meant huge points totals were going to the break that the GC guys were never going to consider.
Take for example this stage:
A GC guy is going to score 0 points here. Yet a breakaway has up to 90 points available (2x 15-point cat.1 summits, 1x 20-point HC summit, 1x 40-point HC summit because it's the last climb of the day, even if it's not going to be decisive).
By contrast, nowadays, MTFs are hugely overvalued and the difference of 33% between cat.1 and HC has been upped to 150% (!). As a result, consider this stage:
This would have had 80 points available in the old system (1x 10-point cat.2 summit, 2x 15-point cat.1 summit, 1x 40-point HC summit because it's the last climb of the day). This is using the double-points system well because GC guys will be fighting each other here and, with time bonuses available on the line, maybe they're going for the stage. This means you could have 40 points available to the break and 40 points available to the GC guys. On the current system there's 50 points available (1x 5-point cat.2 summit, 2x 10-point cat.1 summit, 1x 25-point HC summit), so fewer points, but a similar distribution, so the old and new systems balance out here.
The contrast comes when you then take this stage:
Under the old system, this stage is worth 49 points (3x 3-point cat.4 summits, 1x 40-point HC summit as it's an MTF) but under the new one it's 53 (3x 1-point cat.4 summits, 1x 50-point HC summit). No real difference - but when you compare it to the other stage, the difference becomes clear. The old system has the effective Unipuerto stage with 61,25% the total points available compared to the up-and-down-all-day stage, but the new system has it worth 106% the total points. Winning the MTF is worth the same amount as taking every single summit in a four-climb stage where the Joux-Plane crests 12km from the line.
I would have been more in favour of a refinement of the old system to put more of an emphasis on
winning summits so a bigger gap from 1st to 2nd and 3rd, and only awarding double points within a certain distance of the finish (say 25km as an example). The new system has generated a higher calibre of GPM winner than Anthony Charteau, sure (save for Voeckler, perhaps, who is higher profile as a rider than Charteau but not really a climber), but in my opinion it hasn't really generated a higher calibre of KOM than Rasmussen, Soler or Virenque, and it has come at the expense of all competition for the jersey as it is either competed for by people who have fallen out of the GC mix (Majka, Bardet) or is won by a GC contender almost by accident as a by-product of riding for the GC (Quintana, Froome). And the heavy MTF-weighting means that the fight for the jersey doesn't really start until the final week either.
Benoît Cosnefroy probably can't take the jersey all the way to Paris, but the way the course falls means that nobody's really set out their stall to go for the jersey other than him, yet - and it's stage 14. With how heavily weighted the GPM now is to try to stop a Charteau from winning it, Cosnefroy is probably just happy to get another day of podium time. And you know what, if he works hard enough in week 3 to survive, gets in enough breakaways and manages to collect enough summits from the breakaway to win the jersey, he would be perhaps the least appropriate King of the Mountains of all time, but he would be the most deserving King of the Mountains in years.