This is effectively the business model of every health club out there. They lock you into a 1 year contract, knowing most people will not continue past the first or second month.
In that case, the only incentive they have for you to fail is to pack more gym memberships in the same square footage. Still, I think as a perverse incentive it's a lot more indirect.
Exactly, while they can benefit from having fewer people go regularly to offer a better experience to those who do, churn is still a gym's biggest problem, it's why they lock up longer contracts and why gyms have trainers available and regular progress reports, to enhance customer LTV.