This totally makes sense for one or two people who are hitting the parks commando, but what about the family of five? They're now up to 5x the cost, but they are not "saving" the equivalent 75–100 minutes. They're still only saving the
same 15–20 minutes, assuming they're riding at the same time. The time savings is spread across individuals, while the bill piles up for one individual!
Of course, you could make the kids pay for their own G+....

(actually my teen paid for the G+ and ILLs this summer)