It was a holiday for the McKinsey guys running that thing as well, they appreciated being paid to go waterskiing and BBQing on the beach. For me it was luxury unlike anything I experienced until then - the rooms were so big we had to almost shout to be heard across them, and there was a sofa on the balcony! I took home loads of Hermes toiletries and cologne (I didn't have enough money on my bank account for the room deposit, and one of the consultants had to deposit with his card). In fact we even missed our Paris connection to Dubai, so McKinsey sent a consultant over to baby sit us, which meant taking a Mercedes to the Brasserie La Coupole for an epic feast followed by a night in a neighbouring 5* (I think in the Tour Montparnasse).
Unfortunately, I did not graduate with high enough grades (2.2 on the BA, cutoff was 2.1) for McKinsey, which is why they rejected me the first time. So by the third time they tried to headhunt me, I just told them upfront that their system/HR would reject me because of my grades and it was not worth our time continuing the discussion. They insisted, and it happened as predicted, making me wonder why they still care about that for more senior hires.
There was also a period of time in my life where I accepted conference speaking slots if the hotel was nice enough and close enough to my home. Can't resist a proper 5* hotel lunch buffet, especially if they have giant prawns and olive-roast beef and a decent beer on tap. I made my talks increasingly ridiculous, I think by the end I was explaining Starcraft cheese to middle-aged CTOs and quoting Delta Force founder Col. Charlie Beckwith before following up with droid-driven tractors (all relevant to ML in e-commerce, I promise). They loved it, got voted "best talk of the conference" a couple of times, not hard when 90% of the other talks were "so here's the 3Vs of Big Data" verbatim copied from Wikipedia.
One wonders how a company as rich as McKinsey could have such piss-poor data management. Why not, I dunno, check that the person you're headhunting is already in your database?
Big, cash-loaded companies tend to enact policies more about protecting their wealth and reputation than to actually grow a company or even to keep it efficient. "Good enough" growth and revenue projections are enough to keep people happy and the bonuses coming in. Nobody goes into Big Four style consulting trying to actually change the world unlike at least a fair share of entrepreneurs globally.
These kinds of things play with your ego especially if you're not mature enough to have ever experienced something like it before.
I can tell you that at least at the time the impression given during the interviews was that of a deep, intellectually enriching place. Mostly everyone I talked to went to Stanford, Berkeley, Princeton, or a similarly ranked school. Many of those not straight out of school had come from Google or Facebook. The interview questions were among the hardest and most technically demanding I was asked. You're told of working on problems of massive scale involving true "big data".
On top of this, the budget for seeking out top engineering talent seemed to be without bound. I was flown out and put in a really overly nice hotel room. I was treated to a very expensive steak meal for lunch. I was just one of a very large group of candidates being luxuriously herded through their HQ that day and seemingly every day without end.