The article doesn't really make sense. If a Silver member starts staying more then they will become Gold... maybe what they mean is that they want people who only stay 10 nights a year to still choose Hilton, but if you can't achieve Hilton Gold (by credit card or otherwise) you would be better off with something like hotels.com
It does make sense - not necessarily for a given customer, but for the business. Nassetta's comments were indeed clearly about direct booking channels - getting people off of OTAs has been a big overt push from Hilton for a couple years now ("Stop clicking around" ads, etc.). If they can flip people from OTAs and lock a decent number in at low-level tiers then that is, while small on an individual level, a substantial amount of aggregate revenue. And with those customers already tied to the program, there will be pull-through of some percentage who increase their travel and decide to chase higher tiers with Hilton rather than start afresh elsewhere. Loyalty programs always have been about commitment and aspiration - that's the emotional part that causes consumers to do irrational things.
I have always posited that part of Hilton's loyalty strategy has been reversing the time sequencing of the value proposition. Whereas with most programs you earn status first (incurring no benefits along the way) and then reap the benefits, Hilton has always made it super easy to earn status, so that guests basically always start out with something (whether that be gold, silver, etc.). This is rather smart, IMO, because it shifts the stickiness effect of the program to Day 1 - customers incur switching costs the second that they sign up because they already have status, and they're less likely to go elsewhere after even their first stay.