I thought the same thing. When I first started work a couple of drinks at lunchtime was considered normal. At my first employers (Borland UK) back in the late 80s we would go out as a team every 2-3 weeks and get drunk at the companies expense (slightly unusual but boozy "work" lunches and not going back to the office was still a possibility then).
These days I can't cope with that (my code turns to crap and I want to have a quick nap) but I do like offices were there is a culture of the company paying for a few drinks (Friday afternoons?)
That's a US-centric article. I think those rules will have to be relaxed slightly here in London. Still, leave the heavy drinking for those who want to go on the the pub, which is not strictly a "work event". If your London workplace has much diversity, you may have several co-workers who don't drink at all.
Indeed, although there are extremes here I feel are quite detrimental.
I am not a fan of the "Liquid Lunch" culture I've seen from contractors working for some crown-owned banks who can't pay 200% bonuses this year, nor am I 100% sold on the mandatory company pub-quizz for new media agencies, feels too much like mandatory fun.
Beer trolley OTOH, I'm in :) IIRC the German SAP dev team breakroom is garnished with beer taps. Might explain a lot about ABAP.
London-based companies are doomed.