The analysis of "the gauntlet" also has to include an analysis of the ease of getting into the playoff. It's a natural reaction to think that an MNC recently became twice as hard to get (win B1G title game) and will become twice harder yet (win first round of 4-team playoff). But that's not so, in my view.
Let's say that Ohio State has a uniform 10% chance to finish each of 1st, 2nd, 3rd, or 4th (in the BCS rankings or selection committee's view) after the B1G title game.
Under the old BCS system, they'd have a 20% shot to get into the final game, since 1st and 2nd always get straight into that game and 3rd and 4th are always left out. In the new system they'd be 40% to get into the 4-team playoff, and if they had a 50-50 shot of winning the first round, they end up with the same 20% to get into the final game.
Unless one hypothesizes a fairly strange probability distribution (e.g., "much more likely to finish 1st-2nd than 3rd-4th, but at the same time less likely than 50-50 to win the first round game") the size of the playoff is pretty much irrelevant to the odds of winning the title. In the end there's still exactly one MNC per year, so they haven't become any scarcer.
As a tangent: Similarly, the B1G title game may seem like it makes it hard to win B1G titles, but it depends on how you look at it. It is now easier to win outright B1G titles (there is now one every single year, so they have become less scarce). There's no longer a straight equivalent to a shared B1G title, though based on total number of co-champs over the recent pre-Nebraska years, a berth in the B1G title game could be considered roughly equivalent (and "division co-champ" far easier) if you're trying to compare success across eras.