When I said most people, I meant the people still buying hard copies. They care most about quality.
Even if Disney don't make a ton from this, they're not going to lose money but the analytics they're going to gain is incalculable.
You have a family with Disney+ who watch Frozen on repeat daily, next thing they have an email to the Disney store with a 10% off voucher for an Elsa dress. You have a family with Disney+ who watch Cars on repeat daily, next thing they have an email informing them about Carsland. You have a family with Disney+ who watch the Little Mermaid, next thing they have an email with an offer to stay at Art of Animation.
The data collected could also result in new attractions or meet and greets appearing because of excess popularity previously unseen.
So they might not make a ton from the streaming service but they can more than make up for it in merchandise, park and hotel visits and the more people watch, the more they get invested in the Disney lifestyle. It's a gateway drug that you're paying for.