Well, to be fair, that's only 1 entry per credit card and many don't qualify for an Amex or don't want to pay the higher annual fees associated with these cards.
Gold offers 2 pax entry, platinum 4 pax entry plus international lounge access with the likes of Qatar, Singapore, United, Virgin Atlantic, Air NZ etc (unlike the Amex Velocity card).
VA also makes real world revenue from Amex for the entry also, which is good for the balance sheet. Along with spend based monthly revenue which appears as Velocity points.
Credit cards with higher annual fees, offering single entry to lounges is nothing new, been going on for years and airlines love it.
This doesn't mean their plan to reduce FFS status to higher value pax wont be effective, because that is bound to happen with these changes.
I'm sure they will continue to still offer DSC or TSC from time to time when they want to increase revenue. The overall reduction in lower value FF's will still be achieved either way.