With much less lager fermenting in their vats, they were also producing far less brewer's yeast, the beery by-product that is the main ingredient of Marmite.
I thought they weren't, but even a man with his finger on the pulse of university culture can be forgiven for the occasional error, their bigger lager drinkers in the main, and their favorite haunt is the temperance.
If people want something that's cold and refreshing, and they don't want too much flavor maybe, they don't want anything too hop-forward or they don't want a real ale that might be a little bit warmer, then go for a lager.